63557381 has 4 divisors (see below), whose sum is σ = 64186764. Its totient is φ = 62928000.

The previous prime is 63557371. The next prime is 63557387. The reversal of 63557381 is 18375536.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 61622500 + 1934881 = 7850^2 + 1391^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-63557381 is a prime.

It is a super-2 number, since 2×63557381² = 8079081359158322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (63557387) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 314540 + ... + 314741.

It is an arithmetic number, because the mean of its divisors is an integer number (16046691).

Almost surely, 2^63557381 is an apocalyptic number.

It is an amenable number.

63557381 is a deficient number, since it is larger than the sum of its proper divisors (629383).

63557381 is a wasteful number, since it uses less digits than its factorization.

63557381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 629382.

The product of its digits is 75600, while the sum is 38.

The square root of 63557381 is about 7972.2883164120. The cubic root of 63557381 is about 399.0757431012.

The spelling of 63557381 in words is "sixty-three million, five hundred fifty-seven thousand, three hundred eighty-one".