256261553121 has 8 divisors (see below), whose sum is σ = 390493795264. Its totient is φ = 146435173200.

The previous prime is 256261553101. The next prime is 256261553159. The reversal of 256261553121 is 121355162652.

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

It is not a de Polignac number, because 256261553121 - 2⁷ = 256261552993 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 256261553121.

It is not an unprimeable number, because it can be changed into a prime (256261553101) 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, 6101465530 + ... + 6101465571.

It is an arithmetic number, because the mean of its divisors is an integer number (48811724408).

Almost surely, 2^256261553121 is an apocalyptic number.

256261553121 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

256261553121 is a deficient number, since it is larger than the sum of its proper divisors (134232242143).

256261553121 is a wasteful number, since it uses less digits than its factorization.

256261553121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12202931111.

The product of its digits is 108000, while the sum is 39.

The spelling of 256261553121 in words is "two hundred fifty-six billion, two hundred sixty-one million, five hundred fifty-three thousand, one hundred twenty-one".