1212851640 has 512 divisors, whose sum is σ = 5109350400. Its totient is φ = 222013440.

The previous prime is 1212851639. The next prime is 1212851641. The reversal of 1212851640 is 461582121.

It is an interprime number because it is at equal distance from previous prime (1212851639) and next prime (1212851641).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 1212851598 and 1212851607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1212851641) 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 127 ways as a sum of consecutive naturals, for example, 2762541 + ... + 2762979.

It is an arithmetic number, because the mean of its divisors is an integer number (9979200).

Almost surely, 2^1212851640 is an apocalyptic number.

1212851640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1212851640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2554675200).

1212851640 is an abundant number, since it is smaller than the sum of its proper divisors (3896498760).

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

1212851640 is a wasteful number, since it uses less digits than its factorization.

1212851640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 507 (or 503 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 30.

The square root of 1212851640 is about 34826.0195830646. The cubic root of 1212851640 is about 1066.4386912964.

The spelling of 1212851640 in words is "one billion, two hundred twelve million, eight hundred fifty-one thousand, six hundred forty".