640015626 has 16 divisors (see below), whose sum is σ = 1355327424. Its totient is φ = 200789184.

The previous prime is 640015619. The next prime is 640015633. The reversal of 640015626 is 626510046.

It is an interprime number because it is at equal distance from previous prime (640015619) and next prime (640015633).

It is a junction number, because it is equal to n+sod(n) for n = 640015593 and 640015602.

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, 3137230 + ... + 3137433.

It is an arithmetic number, because the mean of its divisors is an integer number (84707964).

Almost surely, 2^640015626 is an apocalyptic number.

640015626 is an abundant number, since it is smaller than the sum of its proper divisors (715311798).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

640015626 is a wasteful number, since it uses less digits than its factorization.

640015626 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6274685.

The product of its (nonzero) digits is 8640, while the sum is 30.

The square root of 640015626 is about 25298.5301154039. The cubic root of 640015626 is about 861.7808895383.

The spelling of 640015626 in words is "six hundred forty million, fifteen thousand, six hundred twenty-six".