256621667167640 has 16 divisors (see below), whose sum is σ = 577398751127280. Its totient is φ = 102648666867040.

The previous prime is 256621667167633. The next prime is 256621667167669. The reversal of 256621667167640 is 46761766126652.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3207770839556 + ... + 3207770839635.

It is an arithmetic number, because the mean of its divisors is an integer number (36087421945455).

Almost surely, 2^{256621667167640} is an apocalyptic number.

256621667167640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

256621667167640 is an abundant number, since it is smaller than the sum of its proper divisors (320777083959640).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

256621667167640 is a wasteful number, since it uses less digits than its factorization.

256621667167640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6415541679202 (or 6415541679198 counting only the distinct ones).

The product of its (nonzero) digits is 182891520, while the sum is 65.

The spelling of 256621667167640 in words is "two hundred fifty-six trillion, six hundred twenty-one billion, six hundred sixty-seven million, one hundred sixty-seven thousand, six hundred forty".