1256689135690 has 32 divisors (see below), whose sum is σ = 2285339878656. Its totient is φ = 497501937600.

The previous prime is 1256689135687. The next prime is 1256689135703. The reversal of 1256689135690 is 965319866521.

It is a super-2 number, since 2×1256689135690² (a number of 25 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2323789 + ... + 2813071.

It is an arithmetic number, because the mean of its divisors is an integer number (71416871208).

Almost surely, 2^{1256689135690} is an apocalyptic number.

1256689135690 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1256689135690 is a deficient number, since it is larger than the sum of its proper divisors (1028650742966).

1256689135690 is a wasteful number, since it uses less digits than its factorization.

1256689135690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 491934.

The product of its (nonzero) digits is 20995200, while the sum is 61.

The spelling of 1256689135690 in words is "one trillion, two hundred fifty-six billion, six hundred eighty-nine million, one hundred thirty-five thousand, six hundred ninety".