642540015 has 48 divisors (see below), whose sum is σ = 1206773568. Its totient is φ = 314385408.

The previous prime is 642539999. The next prime is 642540053. The reversal of 642540015 is 510045246.

642540015 is a `hidden beast` number, since 642 + 5 + 4 + 0 + 0 + 15 = 666.

It is not a de Polignac number, because 642540015 - 2⁴ = 642539999 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, 94407 + ... + 100983.

It is an arithmetic number, because the mean of its divisors is an integer number (25141116).

Almost surely, 2^642540015 is an apocalyptic number.

642540015 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

642540015 is a deficient number, since it is larger than the sum of its proper divisors (564233553).

642540015 is a wasteful number, since it uses less digits than its factorization.

642540015 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6768 (or 6765 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 27.

The square root of 642540015 is about 25348.3730247130. The cubic root of 642540015 is about 862.9124328699.

The spelling of 642540015 in words is "six hundred forty-two million, five hundred forty thousand, fifteen".