20937491 has 4 divisors (see below), whose sum is σ = 21332592. Its totient is φ = 20542392.

The previous prime is 20937481. The next prime is 20937503. The reversal of 20937491 is 19473902.

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 20937491 - 2²² = 16743187 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20937481) 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, 197471 + ... + 197576.

It is an arithmetic number, because the mean of its divisors is an integer number (5333148).

Almost surely, 2^20937491 is an apocalyptic number.

20937491 is a deficient number, since it is larger than the sum of its proper divisors (395101).

20937491 is an equidigital number, since it uses as much as digits as its factorization.

20937491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 395100.

The product of its (nonzero) digits is 13608, while the sum is 35.

The square root of 20937491 is about 4575.7503209856. The cubic root of 20937491 is about 275.6184033708.

The spelling of 20937491 in words is "twenty million, nine hundred thirty-seven thousand, four hundred ninety-one".