63857621 has 2 divisors, whose sum is σ = 63857622. Its totient is φ = 63857620.

The previous prime is 63857617. The next prime is 63857639. The reversal of 63857621 is 12675836.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 61858225 + 1999396 = 7865^2 + 1414^2 .

It is a cyclic number.

It is not a de Polignac number, because 63857621 - 2² = 63857617 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (63757621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 31928810 + 31928811.

It is an arithmetic number, because the mean of its divisors is an integer number (31928811).

Almost surely, 2^63857621 is an apocalyptic number.

It is an amenable number.

63857621 is a deficient number, since it is larger than the sum of its proper divisors (1).

63857621 is an equidigital number, since it uses as much as digits as its factorization.

63857621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 60480, while the sum is 38.

The square root of 63857621 is about 7991.0963578222. The cubic root of 63857621 is about 399.7031568482.

The spelling of 63857621 in words is "sixty-three million, eight hundred fifty-seven thousand, six hundred twenty-one".