640254515 has 8 divisors (see below), whose sum is σ = 769471728. Its totient is φ = 511426080.

The previous prime is 640254487. The next prime is 640254521. The reversal of 640254515 is 515452046.

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

It is not a de Polignac number, because 640254515 - 2⁶ = 640254451 is a prime.

It is a Duffinian number.

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, 93557 + ... + 100166.

It is an arithmetic number, because the mean of its divisors is an integer number (96183966).

Almost surely, 2^640254515 is an apocalyptic number.

640254515 is a deficient number, since it is larger than the sum of its proper divisors (129217213).

640254515 is a wasteful number, since it uses less digits than its factorization.

640254515 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 194389.

The product of its (nonzero) digits is 24000, while the sum is 32.

The square root of 640254515 is about 25303.2510757017. The cubic root of 640254515 is about 861.8880975281. Note that the first 3 decimals are identical.

The spelling of 640254515 in words is "six hundred forty million, two hundred fifty-four thousand, five hundred fifteen".