1664867636 has 12 divisors (see below), whose sum is σ = 2981274912. Its totient is φ = 813074808.

The previous prime is 1664867623. The next prime is 1664867639. The reversal of 1664867636 is 6367684661.

It is a happy number.

It is a hoax number, since the sum of its digits (53) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1664867639) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4839560 + ... + 4839903.

It is an arithmetic number, because the mean of its divisors is an integer number (248439576).

Almost surely, 2^1664867636 is an apocalyptic number.

It is an amenable number.

1664867636 is a deficient number, since it is larger than the sum of its proper divisors (1316407276).

1664867636 is a wasteful number, since it uses less digits than its factorization.

1664867636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9679510 (or 9679508 counting only the distinct ones).

The product of its digits is 5225472, while the sum is 53.

The square root of 1664867636 is about 40802.7895614993. The cubic root of 1664867636 is about 1185.2043505700.

The spelling of 1664867636 in words is "one billion, six hundred sixty-four million, eight hundred sixty-seven thousand, six hundred thirty-six".