20993337 has 10 divisors (see below), whose sum is σ = 31360538. Its totient is φ = 13995504.

The previous prime is 20993281. The next prime is 20993339. The reversal of 20993337 is 73339902.

It can be written as a sum of positive squares in only one way, i.e., 17214201 + 3779136 = 4149^2 + 1944^2 .

It is not a de Polignac number, because 20993337 - 2¹⁶ = 20927801 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20993339) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 129508 + ... + 129669.

Almost surely, 2^20993337 is an apocalyptic number.

20993337 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

It is an amenable number.

20993337 is a deficient number, since it is larger than the sum of its proper divisors (10367201).

20993337 is an equidigital number, since it uses as much as digits as its factorization.

20993337 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 259189 (or 259180 counting only the distinct ones).

The product of its (nonzero) digits is 30618, while the sum is 36.

The square root of 20993337 is about 4581.8486443793. The cubic root of 20993337 is about 275.8632356440.

The spelling of 20993337 in words is "twenty million, nine hundred ninety-three thousand, three hundred thirty-seven".