20993637 has 16 divisors (see below), whose sum is σ = 32054400. Its totient is φ = 11972352.

The previous prime is 20993633. The next prime is 20993663. The reversal of 20993637 is 73639902.

It is not a de Polignac number, because 20993637 - 2² = 20993633 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20993595 and 20993604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20993633) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19489 + ... + 20537.

It is an arithmetic number, because the mean of its divisors is an integer number (2003400).

Almost surely, 2^20993637 is an apocalyptic number.

It is an amenable number.

20993637 is a deficient number, since it is larger than the sum of its proper divisors (11060763).

20993637 is a wasteful number, since it uses less digits than its factorization.

20993637 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2012.

The product of its (nonzero) digits is 61236, while the sum is 39.

The square root of 20993637 is about 4581.8813821399. The cubic root of 20993637 is about 275.8645496891.

The spelling of 20993637 in words is "twenty million, nine hundred ninety-three thousand, six hundred thirty-seven".