621798656 has 18 divisors (see below), whose sum is σ = 1241168922. Its totient is φ = 310899200.

The previous prime is 621798649. The next prime is 621798677. The reversal of 621798656 is 656897126.

It can be written as a sum of positive squares in only one way, i.e., 352838656 + 268960000 = 18784^2 + 16400^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1214195 + ... + 1214706.

It is an arithmetic number, because the mean of its divisors is an integer number (68953829).

Almost surely, 2^621798656 is an apocalyptic number.

It is an amenable number.

621798656 is a deficient number, since it is larger than the sum of its proper divisors (619370266).

621798656 is an equidigital number, since it uses as much as digits as its factorization.

621798656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2428917 (or 2428903 counting only the distinct ones).

The product of its digits is 1088640, while the sum is 50.

The square root of 621798656 is about 24935.8909205186. The cubic root of 621798656 is about 853.5256814663.

The spelling of 621798656 in words is "six hundred twenty-one million, seven hundred ninety-eight thousand, six hundred fifty-six".