255721897690 has 32 divisors (see below), whose sum is σ = 557000976384. Its totient is φ = 82518662400.

The previous prime is 255721897687. The next prime is 255721897721. The reversal of 255721897690 is 96798127552.

It is a super-2 number, since 2×255721897690² (a number of 24 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 107444986 + ... + 107447365.

It is an arithmetic number, because the mean of its divisors is an integer number (17406280512).

Almost surely, 2^255721897690 is an apocalyptic number.

255721897690 is an abundant number, since it is smaller than the sum of its proper divisors (301279078694).

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

255721897690 is a wasteful number, since it uses less digits than its factorization.

255721897690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 214892382.

The product of its (nonzero) digits is 19051200, while the sum is 61.

The spelling of 255721897690 in words is "two hundred fifty-five billion, seven hundred twenty-one million, eight hundred ninety-seven thousand, six hundred ninety".