20654891 has 2 divisors, whose sum is σ = 20654892. Its totient is φ = 20654890.

The previous prime is 20654863. The next prime is 20654903. The reversal of 20654891 is 19845602.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20654891 - 2¹⁴ = 20638507 is a prime.

It is not a weakly prime, because it can be changed into another prime (20654801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10327445 + 10327446.

It is an arithmetic number, because the mean of its divisors is an integer number (10327446).

Almost surely, 2^20654891 is an apocalyptic number.

20654891 is a deficient number, since it is larger than the sum of its proper divisors (1).

20654891 is an equidigital number, since it uses as much as digits as its factorization.

20654891 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17280, while the sum is 35.

The square root of 20654891 is about 4544.7652304602. The cubic root of 20654891 is about 274.3727455740.

The spelling of 20654891 in words is "twenty million, six hundred fifty-four thousand, eight hundred ninety-one".