20640632 has 8 divisors (see below), whose sum is σ = 38701200. Its totient is φ = 10320312.

The previous prime is 20640617. The next prime is 20640647. The reversal of 20640632 is 23604602.

It is an interprime number because it is at equal distance from previous prime (20640617) and next prime (20640647).

It is a tau number, because it is divible by the number of its divisors (8).

It is a junction number, because it is equal to n+sod(n) for n = 20640598 and 20640607.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1290032 + ... + 1290047.

It is an arithmetic number, because the mean of its divisors is an integer number (4837650).

Almost surely, 2^20640632 is an apocalyptic number.

It is an amenable number.

20640632 is a deficient number, since it is larger than the sum of its proper divisors (18060568).

20640632 is a wasteful number, since it uses less digits than its factorization.

20640632 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2580085 (or 2580081 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 23.

The square root of 20640632 is about 4543.1962317294. The cubic root of 20640632 is about 274.3095937584.

The spelling of 20640632 in words is "twenty million, six hundred forty thousand, six hundred thirty-two".