1642664444 has 24 divisors (see below), whose sum is σ = 2911505520. Its totient is φ = 810860544.

The previous prime is 1642664417. The next prime is 1642664473. The reversal of 1642664444 is 4444662461.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 116732 + ... + 130044.

It is an arithmetic number, because the mean of its divisors is an integer number (121312730).

Almost surely, 2^1642664444 is an apocalyptic number.

It is an amenable number.

1642664444 is a deficient number, since it is larger than the sum of its proper divisors (1268841076).

1642664444 is a wasteful number, since it uses less digits than its factorization.

1642664444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13709 (or 13707 counting only the distinct ones).

The product of its digits is 442368, while the sum is 41.

The square root of 1642664444 is about 40529.7969893756. The cubic root of 1642664444 is about 1179.9120024391.

The spelling of 1642664444 in words is "one billion, six hundred forty-two million, six hundred sixty-four thousand, four hundred forty-four".