639421320015 has 48 divisors (see below), whose sum is σ = 1206893282400. Its totient is φ = 311935470336.

The previous prime is 639421320007. The next prime is 639421320023. The reversal of 639421320015 is 510023124936.

639421320015 is a `hidden beast` number, since 639 + 4 + 2 + 1 + 3 + 2 + 0 + 0 + 15 = 666.

639421320015 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (639421320007) and next prime (639421320023).

It is not a de Polignac number, because 639421320015 - 2³ = 639421320007 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 12869364 + ... + 12918953.

It is an arithmetic number, because the mean of its divisors is an integer number (25143610050).

Almost surely, 2^639421320015 is an apocalyptic number.

639421320015 is a deficient number, since it is larger than the sum of its proper divisors (567471962385).

639421320015 is a wasteful number, since it uses less digits than its factorization.

639421320015 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25788376 (or 25788373 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 36.

The spelling of 639421320015 in words is "six hundred thirty-nine billion, four hundred twenty-one million, three hundred twenty thousand, fifteen".