640257610 has 16 divisors (see below), whose sum is σ = 1153053000. Its totient is φ = 255972096.

The previous prime is 640257589. The next prime is 640257637. The reversal of 640257610 is 16752046.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 453306681 + 186950929 = 21291^2 + 13673^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5566 + ... + 36214.

Almost surely, 2^640257610 is an apocalyptic number.

640257610 is a deficient number, since it is larger than the sum of its proper divisors (512795390).

640257610 is a wasteful number, since it uses less digits than its factorization.

640257610 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32745.

The product of its (nonzero) digits is 10080, while the sum is 31.

The square root of 640257610 is about 25303.3122337768. The cubic root of 640257610 is about 861.8894863193.

It can be divided in two parts, 6402 and 57610, that multiplied together give a triangular number (368819220 = T₂₇₁₅₉).

The spelling of 640257610 in words is "six hundred forty million, two hundred fifty-seven thousand, six hundred ten".