256651643031 has 8 divisors (see below), whose sum is σ = 391088217984. Its totient is φ = 146658081720.

The previous prime is 256651642999. The next prime is 256651643081. The reversal of 256651643031 is 130346156652.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 256651643031 - 2⁵ = 256651642999 is a prime.

It is a super-2 number, since 2×256651643031² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256651643081) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6110753385 + ... + 6110753426.

It is an arithmetic number, because the mean of its divisors is an integer number (48886027248).

Almost surely, 2^256651643031 is an apocalyptic number.

256651643031 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

256651643031 is a deficient number, since it is larger than the sum of its proper divisors (134436574953).

256651643031 is a wasteful number, since it uses less digits than its factorization.

256651643031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12221506821.

The product of its (nonzero) digits is 388800, while the sum is 42.

Adding to 256651643031 its reverse (130346156652), we get a palindrome (386997799683).

The spelling of 256651643031 in words is "two hundred fifty-six billion, six hundred fifty-one million, six hundred forty-three thousand, thirty-one".