655642690 has 16 divisors (see below), whose sum is σ = 1242270720. Its totient is φ = 248454000.

The previous prime is 655642667. The next prime is 655642693. The reversal of 655642690 is 96246556.

It is a super-2 number, since 2×655642690² = 859734673900872200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (655642693) 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, 1725186 + ... + 1725565.

It is an arithmetic number, because the mean of its divisors is an integer number (77641920).

Almost surely, 2^655642690 is an apocalyptic number.

655642690 is a deficient number, since it is larger than the sum of its proper divisors (586628030).

655642690 is a wasteful number, since it uses less digits than its factorization.

655642690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3450777.

The product of its (nonzero) digits is 388800, while the sum is 43.

The square root of 655642690 is about 25605.5206937879. The cubic root of 655642690 is about 868.7385117263.

The spelling of 655642690 in words is "six hundred fifty-five million, six hundred forty-two thousand, six hundred ninety".