655647720 has 128 divisors (see below), whose sum is σ = 2420893440. Its totient is φ = 138332160.

The previous prime is 655647701. The next prime is 655647739. The reversal of 655647720 is 27746556.

It is an interprime number because it is at equal distance from previous prime (655647701) and next prime (655647739).

It is a Harshad number since it is a multiple of its sum of digits (42).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 19101 + ... + 40940.

It is an arithmetic number, because the mean of its divisors is an integer number (18913230).

Almost surely, 2^655647720 is an apocalyptic number.

655647720 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

655647720 is an abundant number, since it is smaller than the sum of its proper divisors (1765245720).

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

655647720 is a wasteful number, since it uses less digits than its factorization.

655647720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60075 (or 60071 counting only the distinct ones).

The product of its (nonzero) digits is 352800, while the sum is 42.

The square root of 655647720 is about 25605.6189146054. The cubic root of 655647720 is about 868.7407333346.

The spelling of 655647720 in words is "six hundred fifty-five million, six hundred forty-seven thousand, seven hundred twenty".