63991399515 has 8 divisors (see below), whose sum is σ = 102386239248. Its totient is φ = 34128746400.

The previous prime is 63991399463. The next prime is 63991399529. The reversal of 63991399515 is 51599319936.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 63991399515 - 2⁷ = 63991399387 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2133046636 + ... + 2133046665.

It is an arithmetic number, because the mean of its divisors is an integer number (12798279906).

Almost surely, 2^63991399515 is an apocalyptic number.

63991399515 is a deficient number, since it is larger than the sum of its proper divisors (38394839733).

63991399515 is a wasteful number, since it uses less digits than its factorization.

63991399515 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4266093309.

The product of its digits is 8857350, while the sum is 60.

The spelling of 63991399515 in words is "sixty-three billion, nine hundred ninety-one million, three hundred ninety-nine thousand, five hundred fifteen".