1256997986 has 24 divisors (see below), whose sum is σ = 2045592576. Its totient is φ = 578930240.

The previous prime is 1256997983. The next prime is 1256998007. The reversal of 1256997986 is 6897996521.

It is not an unprimeable number, because it can be changed into a prime (1256997983) 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, 4031 + ... + 50301.

It is an arithmetic number, because the mean of its divisors is an integer number (85233024).

Almost surely, 2^1256997986 is an apocalyptic number.

1256997986 is a deficient number, since it is larger than the sum of its proper divisors (788594590).

1256997986 is a wasteful number, since it uses less digits than its factorization.

1256997986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46354 (or 46337 counting only the distinct ones).

The product of its digits is 14696640, while the sum is 62.

The square root of 1256997986 is about 35454.1673996161. The cubic root of 1256997986 is about 1079.2238324688.

The spelling of 1256997986 in words is "one billion, two hundred fifty-six million, nine hundred ninety-seven thousand, nine hundred eighty-six".