20605631 has 8 divisors (see below), whose sum is σ = 22243680. Its totient is φ = 19029472.

The previous prime is 20605621. The next prime is 20605661. The reversal of 20605631 is 13650602.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20605631 is a prime.

It is a super-2 number, since 2×20605631² = 849184057816322, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20605597 and 20605606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20605601) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14780 + ... + 16113.

It is an arithmetic number, because the mean of its divisors is an integer number (2780460).

Almost surely, 2^20605631 is an apocalyptic number.

20605631 is a deficient number, since it is larger than the sum of its proper divisors (1638049).

20605631 is a wasteful number, since it uses less digits than its factorization.

20605631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30945.

The product of its (nonzero) digits is 1080, while the sum is 23.

The square root of 20605631 is about 4539.3425735452. The cubic root of 20605631 is about 274.1544540938.

The spelling of 20605631 in words is "twenty million, six hundred five thousand, six hundred thirty-one".