63557321 has 4 divisors (see below), whose sum is σ = 63585552. Its totient is φ = 63529092.

The previous prime is 63557309. The next prime is 63557323. The reversal of 63557321 is 12375536.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-63557321 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (63557323) 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, 10415 + ... + 15348.

It is an arithmetic number, because the mean of its divisors is an integer number (15896388).

Almost surely, 2^63557321 is an apocalyptic number.

It is an amenable number.

63557321 is a deficient number, since it is larger than the sum of its proper divisors (28231).

63557321 is a wasteful number, since it uses less digits than its factorization.

63557321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28230.

The product of its digits is 18900, while the sum is 32.

The square root of 63557321 is about 7972.2845533762. The cubic root of 63557321 is about 399.0756175215.

The spelling of 63557321 in words is "sixty-three million, five hundred fifty-seven thousand, three hundred twenty-one".