644429092 has 6 divisors (see below), whose sum is σ = 1127750918. Its totient is φ = 322214544.

The previous prime is 644429087. The next prime is 644429101. The reversal of 644429092 is 290924446.

It can be written as a sum of positive squares in only one way, i.e., 595652836 + 48776256 = 24406^2 + 6984^2 .

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 as a sum of consecutive naturals, namely, 80553633 + ... + 80553640.

Almost surely, 2^644429092 is an apocalyptic number.

It is an amenable number.

644429092 is a deficient number, since it is larger than the sum of its proper divisors (483321826).

644429092 is a wasteful number, since it uses less digits than its factorization.

644429092 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 161107277 (or 161107275 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 40.

The square root of 644429092 is about 25385.6079698714. The cubic root of 644429092 is about 863.7572638440.

The spelling of 644429092 in words is "six hundred forty-four million, four hundred twenty-nine thousand, ninety-two".