655725640 has 32 divisors (see below), whose sum is σ = 1522978560. Its totient is φ = 253828800.

The previous prime is 655725617. The next prime is 655725643. The reversal of 655725640 is 46527556.

It is a super-2 number, since 2×655725640² = 859952229906819200, which contains 22 as substring.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 655725593 and 655725602.

It is not an unprimeable number, because it can be changed into a prime (655725643) 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, 263166 + ... + 265645.

It is an arithmetic number, because the mean of its divisors is an integer number (47593080).

Almost surely, 2^655725640 is an apocalyptic number.

It is an amenable number.

655725640 is an abundant number, since it is smaller than the sum of its proper divisors (867252920).

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

655725640 is a wasteful number, since it uses less digits than its factorization.

655725640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 528853 (or 528849 counting only the distinct ones).

The product of its (nonzero) digits is 252000, while the sum is 40.

The square root of 655725640 is about 25607.1404104402. The cubic root of 655725640 is about 868.7751469353.

The spelling of 655725640 in words is "six hundred fifty-five million, seven hundred twenty-five thousand, six hundred forty".