20968491 has 4 divisors (see below), whose sum is σ = 27957992. Its totient is φ = 13978992.

The previous prime is 20968481. The next prime is 20968499. The reversal of 20968491 is 19486902.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 20968491 - 2⁶ = 20968427 is a prime.

It is a super-2 number, since 2×20968491² = 879355229634162, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20968499) 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, 3494746 + ... + 3494751.

It is an arithmetic number, because the mean of its divisors is an integer number (6989498).

Almost surely, 2^20968491 is an apocalyptic number.

20968491 is a deficient number, since it is larger than the sum of its proper divisors (6989501).

20968491 is an equidigital number, since it uses as much as digits as its factorization.

20968491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6989500.

The product of its (nonzero) digits is 31104, while the sum is 39.

The square root of 20968491 is about 4579.1364906497. The cubic root of 20968491 is about 275.7543629460.

The spelling of 20968491 in words is "twenty million, nine hundred sixty-eight thousand, four hundred ninety-one".