63991995 has 16 divisors (see below), whose sum is σ = 108410400. Its totient is φ = 32121344.

The previous prime is 63991973. The next prime is 63991997. The reversal of 63991995 is 59919936.

It is a cyclic number.

It is not a de Polignac number, because 63991995 - 2⁹ = 63991483 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is not an unprimeable number, because it can be changed into a prime (63991997) 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, 125220 + ... + 125729.

It is an arithmetic number, because the mean of its divisors is an integer number (6775650).

Almost surely, 2^63991995 is an apocalyptic number.

63991995 is a deficient number, since it is larger than the sum of its proper divisors (44418405).

63991995 is a wasteful number, since it uses less digits than its factorization.

63991995 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 250974.

The product of its digits is 590490, while the sum is 51.

The square root of 63991995 is about 7999.4996718545. The cubic root of 63991995 is about 399.9833222213.

The spelling of 63991995 in words is "sixty-three million, nine hundred ninety-one thousand, nine hundred ninety-five".