63420921 has 16 divisors (see below), whose sum is σ = 94086720. Its totient is φ = 42222240.

The previous prime is 63420893. The next prime is 63420937. The reversal of 63420921 is 12902436.

63420921 is a `hidden beast` number, since 634 + 2 + 0 + 9 + 21 = 666.

It is not a de Polignac number, because 63420921 - 2¹⁵ = 63388153 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (63420961) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 28381 + ... + 30533.

It is an arithmetic number, because the mean of its divisors is an integer number (5880420).

Almost surely, 2^63420921 is an apocalyptic number.

It is an amenable number.

63420921 is a deficient number, since it is larger than the sum of its proper divisors (30665799).

63420921 is a wasteful number, since it uses less digits than its factorization.

63420921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3253 (or 3247 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 27.

The square root of 63420921 is about 7963.7253217323. The cubic root of 63420921 is about 398.7899284250.

The spelling of 63420921 in words is "sixty-three million, four hundred twenty thousand, nine hundred twenty-one".