640156250 has 64 divisors (see below), whose sum is σ = 1276168608. Its totient is φ = 240000000.

The previous prime is 640156243. The next prime is 640156273. The reversal of 640156250 is 52651046.

It can be written as a sum of positive squares in 16 ways, for example, as 620557921 + 19598329 = 24911^2 + 4427^2 .

It is a sliding number, since 640156250 = 156250 + 640000000 and 1/156250 + 1/640000000 = 0.00000640156250.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2656130 + ... + 2656370.

Almost surely, 2^640156250 is an apocalyptic number.

640156250 is a deficient number, since it is larger than the sum of its proper divisors (636012358).

640156250 is an frugal number, since it uses more digits than its factorization.

640156250 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 295 (or 265 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 29.

The square root of 640156250 is about 25301.3092546611. The cubic root of 640156250 is about 861.8440016438.

It can be divided in two parts, 640 and 156250, that multiplied together give a 8-th power (100000000 = 10⁸).

The spelling of 640156250 in words is "six hundred forty million, one hundred fifty-six thousand, two hundred fifty".