655400561 has 2 divisors, whose sum is σ = 655400562. Its totient is φ = 655400560.

The previous prime is 655400533. The next prime is 655400567. The reversal of 655400561 is 165004556.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 421891600 + 233508961 = 20540^2 + 15281^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-655400561 is a prime.

It is a super-2 number, since 2×655400561² = 859099790718229442, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (655400567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 327700280 + 327700281.

It is an arithmetic number, because the mean of its divisors is an integer number (327700281).

Almost surely, 2^655400561 is an apocalyptic number.

It is an amenable number.

655400561 is a deficient number, since it is larger than the sum of its proper divisors (1).

655400561 is an equidigital number, since it uses as much as digits as its factorization.

655400561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18000, while the sum is 32.

The square root of 655400561 is about 25600.7921947740. The cubic root of 655400561 is about 868.6315567800.

The spelling of 655400561 in words is "six hundred fifty-five million, four hundred thousand, five hundred sixty-one".