63964021 has 4 divisors (see below), whose sum is σ = 69778944. Its totient is φ = 58149100.

The previous prime is 63964003. The next prime is 63964037. The reversal of 63964021 is 12046936.

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 not a de Polignac number, because 63964021 - 2¹⁵ = 63931253 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (63964001) 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, 2907445 + ... + 2907466.

It is an arithmetic number, because the mean of its divisors is an integer number (17444736).

Almost surely, 2^63964021 is an apocalyptic number.

It is an amenable number.

63964021 is a deficient number, since it is larger than the sum of its proper divisors (5814923).

63964021 is a wasteful number, since it uses less digits than its factorization.

63964021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5814922.

The product of its (nonzero) digits is 7776, while the sum is 31.

The square root of 63964021 is about 7997.7509963739. The cubic root of 63964021 is about 399.9250296995.

The spelling of 63964021 in words is "sixty-three million, nine hundred sixty-four thousand, twenty-one".