1264156879 has 4 divisors (see below), whose sum is σ = 1264965184. Its totient is φ = 1263348576.

The previous prime is 1264156819. The next prime is 1264156903. The reversal of 1264156879 is 9786514621.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1264156879 is a prime.

It is a super-2 number, since 2×1264156879² = 3196185229446041282, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1264156819) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 401802 + ... + 404935.

It is an arithmetic number, because the mean of its divisors is an integer number (316241296).

Almost surely, 2^1264156879 is an apocalyptic number.

1264156879 is a deficient number, since it is larger than the sum of its proper divisors (808305).

1264156879 is an equidigital number, since it uses as much as digits as its factorization.

1264156879 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 808304.

The product of its digits is 725760, while the sum is 49.

The square root of 1264156879 is about 35554.9838841195. The cubic root of 1264156879 is about 1081.2687646670.

The spelling of 1264156879 in words is "one billion, two hundred sixty-four million, one hundred fifty-six thousand, eight hundred seventy-nine".