63975821 has 24 divisors (see below), whose sum is σ = 81396000. Its totient is φ = 49829472.

The previous prime is 63975797. The next prime is 63975839. The reversal of 63975821 is 12857936.

It is a de Polignac number, because none of the positive numbers 2^k-63975821 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (63975851) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 41930 + ... + 43428.

It is an arithmetic number, because the mean of its divisors is an integer number (3391500).

Almost surely, 2^63975821 is an apocalyptic number.

It is an amenable number.

63975821 is a deficient number, since it is larger than the sum of its proper divisors (17420179).

63975821 is a wasteful number, since it uses less digits than its factorization.

63975821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1593 (or 1586 counting only the distinct ones).

The product of its digits is 90720, while the sum is 41.

The square root of 63975821 is about 7998.4886697426. The cubic root of 63975821 is about 399.9496207384.

The spelling of 63975821 in words is "sixty-three million, nine hundred seventy-five thousand, eight hundred twenty-one".