644760492610 has 32 divisors (see below), whose sum is σ = 1257804242352. Its totient is φ = 236549064960.

The previous prime is 644760492599. The next prime is 644760492641. The reversal of 644760492610 is 16294067446.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 253551524521 + 391208968089 = 503539^2 + 625467^2 .

It is a super-2 number, since 2×644760492610² (a number of 24 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15774801 + ... + 15815620.

Almost surely, 2^644760492610 is an apocalyptic number.

644760492610 is a deficient number, since it is larger than the sum of its proper divisors (613043749742).

644760492610 is a wasteful number, since it uses less digits than its factorization.

644760492610 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31590598.

The product of its (nonzero) digits is 1741824, while the sum is 49.

The spelling of 644760492610 in words is "six hundred forty-four billion, seven hundred sixty million, four hundred ninety-two thousand, six hundred ten".