655885621 has 2 divisors, whose sum is σ = 655885622. Its totient is φ = 655885620.

The previous prime is 655885613. The next prime is 655885673. The reversal of 655885621 is 126588556.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 444619396 + 211266225 = 21086^2 + 14535^2 .

It is a cyclic number.

It is not a de Polignac number, because 655885621 - 2³ = 655885613 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (655882621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 327942810 + 327942811.

It is an arithmetic number, because the mean of its divisors is an integer number (327942811).

Almost surely, 2^655885621 is an apocalyptic number.

It is an amenable number.

655885621 is a deficient number, since it is larger than the sum of its proper divisors (1).

655885621 is an equidigital number, since it uses as much as digits as its factorization.

655885621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 576000, while the sum is 46.

The square root of 655885621 is about 25610.2639775540. The cubic root of 655885621 is about 868.8457944778.

The spelling of 655885621 in words is "six hundred fifty-five million, eight hundred eighty-five thousand, six hundred twenty-one".