656912820 has 48 divisors (see below), whose sum is σ = 1850667840. Its totient is φ = 174099456.

The previous prime is 656912813. The next prime is 656912831. The reversal of 656912820 is 28219656.

It is a super-3 number, since 3×656912820³ (a number of 27 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23805 + ... + 43364.

It is an arithmetic number, because the mean of its divisors is an integer number (38555580).

Almost surely, 2^656912820 is an apocalyptic number.

656912820 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

656912820 is an abundant number, since it is smaller than the sum of its proper divisors (1193755020).

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

656912820 is a wasteful number, since it uses less digits than its factorization.

656912820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67344 (or 67342 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 39.

The square root of 656912820 is about 25630.3105716649. The cubic root of 656912820 is about 869.2991316640.

The spelling of 656912820 in words is "six hundred fifty-six million, nine hundred twelve thousand, eight hundred twenty".