1664136444 has 24 divisors (see below), whose sum is σ = 3904443088. Its totient is φ = 551646720.

The previous prime is 1664136437. The next prime is 1664136469. The reversal of 1664136444 is 4446314661.

It is a nude number because it is divisible by every one of its digits.

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, 380917 + ... + 385260.

Almost surely, 2^1664136444 is an apocalyptic number.

It is an amenable number.

1664136444 is an abundant number, since it is smaller than the sum of its proper divisors (2240306644).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1664136444 is a wasteful number, since it uses less digits than its factorization.

1664136444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 766365 (or 766363 counting only the distinct ones).

The product of its digits is 165888, while the sum is 39.

The square root of 1664136444 is about 40793.8285038313. The cubic root of 1664136444 is about 1185.0308154852.

The spelling of 1664136444 in words is "one billion, six hundred sixty-four million, one hundred thirty-six thousand, four hundred forty-four".