655447640 has 32 divisors (see below), whose sum is σ = 1481107680. Its totient is φ = 261050112.

The previous prime is 655447619. The next prime is 655447679. The reversal of 655447640 is 46744556.

It is a happy number.

655447640 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×655447640² = 859223217563139200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25844 + ... + 44483.

It is an arithmetic number, because the mean of its divisors is an integer number (46284615).

Almost surely, 2^655447640 is an apocalyptic number.

It is an amenable number.

655447640 is an abundant number, since it is smaller than the sum of its proper divisors (825660040).

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

655447640 is a wasteful number, since it uses less digits than its factorization.

655447640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70571 (or 70567 counting only the distinct ones).

The product of its (nonzero) digits is 403200, while the sum is 41.

The square root of 655447640 is about 25601.7116615276. The cubic root of 655447640 is about 868.6523549140.

The spelling of 655447640 in words is "six hundred fifty-five million, four hundred forty-seven thousand, six hundred forty".