256153861 has 4 divisors (see below), whose sum is σ = 259662892. Its totient is φ = 252644832.

The previous prime is 256153753. The next prime is 256153867. The reversal of 256153861 is 168351652.

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

It can be written as a sum of positive squares in 2 ways, for example, as 162180225 + 93973636 = 12735^2 + 9694^2 .

It is a cyclic number.

It is not a de Polignac number, because 256153861 - 2⁹ = 256153349 is a prime.

It is a super-2 number, since 2×256153861² = 131229601010414642, which contains 22 as substring.

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 256153861.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256153867) 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, 1754406 + ... + 1754551.

It is an arithmetic number, because the mean of its divisors is an integer number (64915723).

Almost surely, 2^256153861 is an apocalyptic number.

It is an amenable number.

256153861 is a deficient number, since it is larger than the sum of its proper divisors (3509031).

256153861 is an equidigital number, since it uses as much as digits as its factorization.

256153861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3509030.

The product of its digits is 43200, while the sum is 37.

The square root of 256153861 is about 16004.8074340181. The cubic root of 256153861 is about 635.0876031825.

The spelling of 256153861 in words is "two hundred fifty-six million, one hundred fifty-three thousand, eight hundred sixty-one".