1663626631 has 4 divisors (see below), whose sum is σ = 1687058064. Its totient is φ = 1640195200.

The previous prime is 1663626583. The next prime is 1663626649. The reversal of 1663626631 is 1366263661.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1663626631 - 2⁹ = 1663626119 is a prime.

It is a super-2 number, since 2×1663626631² = 5535307134744820322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1663626661) 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, 11715610 + ... + 11715751.

It is an arithmetic number, because the mean of its divisors is an integer number (421764516).

Almost surely, 2^1663626631 is an apocalyptic number.

1663626631 is a deficient number, since it is larger than the sum of its proper divisors (23431433).

1663626631 is an equidigital number, since it uses as much as digits as its factorization.

1663626631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23431432.

The product of its digits is 139968, while the sum is 40.

The square root of 1663626631 is about 40787.5793716666. The cubic root of 1663626631 is about 1184.9097905894.

The spelling of 1663626631 in words is "one billion, six hundred sixty-three million, six hundred twenty-six thousand, six hundred thirty-one".