1640342644 has 12 divisors (see below), whose sum is σ = 2871229284. Its totient is φ = 819991424.

The previous prime is 1640342623. The next prime is 1640342663. The reversal of 1640342644 is 4462430461.

It can be written as a sum of positive squares in 2 ways, for example, as 188732644 + 1451610000 = 13738^2 + 38100^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23299 + ... + 61834.

It is an arithmetic number, because the mean of its divisors is an integer number (239269107).

Almost surely, 2^1640342644 is an apocalyptic number.

It is an amenable number.

1640342644 is a deficient number, since it is larger than the sum of its proper divisors (1230886640).

1640342644 is a wasteful number, since it uses less digits than its factorization.

1640342644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89954 (or 89952 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 34.

The square root of 1640342644 is about 40501.1437369366. The cubic root of 1640342644 is about 1179.3558305394.

The spelling of 1640342644 in words is "one billion, six hundred forty million, three hundred forty-two thousand, six hundred forty-four".