256164213506 has 16 divisors (see below), whose sum is σ = 396783138048. Its totient is φ = 123906121200.

The previous prime is 256164213479. The next prime is 256164213509. The reversal of 256164213506 is 605312461652.

It is a happy number.

It is a super-2 number, since 2×256164213506² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (256164213509) 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, 563225 + ... + 910796.

It is an arithmetic number, because the mean of its divisors is an integer number (24798946128).

Almost surely, 2^256164213506 is an apocalyptic number.

256164213506 is a deficient number, since it is larger than the sum of its proper divisors (140618924542).

256164213506 is a wasteful number, since it uses less digits than its factorization.

256164213506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1476857.

The product of its (nonzero) digits is 259200, while the sum is 41.

The spelling of 256164213506 in words is "two hundred fifty-six billion, one hundred sixty-four million, two hundred thirteen thousand, five hundred six".