1266212820 has 48 divisors (see below), whose sum is σ = 3731999040. Its totient is φ = 319885056.

The previous prime is 1266212789. The next prime is 1266212837. The reversal of 1266212820 is 282126621.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 554217 + ... + 556496.

It is an arithmetic number, because the mean of its divisors is an integer number (77749980).

Almost surely, 2^1266212820 is an apocalyptic number.

1266212820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1266212820 is an abundant number, since it is smaller than the sum of its proper divisors (2465786220).

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

1266212820 is a wasteful number, since it uses less digits than its factorization.

1266212820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1110744 (or 1110742 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 30.

The square root of 1266212820 is about 35583.8842736428. The cubic root of 1266212820 is about 1081.8546151479.

The spelling of 1266212820 in words is "one billion, two hundred sixty-six million, two hundred twelve thousand, eight hundred twenty".