1261021212 has 36 divisors (see below), whose sum is σ = 3477362616. Its totient is φ = 382127520.

The previous prime is 1261021211. The next prime is 1261021213. The reversal of 1261021212 is 2121201621.

1261021212 is a `hidden beast` number, since 12 + 610 + 21 + 21 + 2 = 666.

It is an interprime number because it is at equal distance from previous prime (1261021211) and next prime (1261021213).

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×1261021212² = 3180348994227897888, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1261021211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1591803 + ... + 1592594.

It is an arithmetic number, because the mean of its divisors is an integer number (96593406).

Almost surely, 2^1261021212 is an apocalyptic number.

1261021212 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1261021212 is an abundant number, since it is smaller than the sum of its proper divisors (2216341404).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1261021212 is a wasteful number, since it uses less digits than its factorization.

1261021212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3184418 (or 3184413 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

The square root of 1261021212 is about 35510.8604795772. The cubic root of 1261021212 is about 1080.3740165493.

Adding to 1261021212 its reverse (2121201621), we get a palindrome (3382222833).

The spelling of 1261021212 in words is "one billion, two hundred sixty-one million, twenty-one thousand, two hundred twelve".