20993111 has 2 divisors, whose sum is σ = 20993112. Its totient is φ = 20993110.

The previous prime is 20993087. The next prime is 20993123. The reversal of 20993111 is 11139902.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20993111 - 2⁶ = 20993047 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20993131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10496555 + 10496556.

It is an arithmetic number, because the mean of its divisors is an integer number (10496556).

Almost surely, 2^20993111 is an apocalyptic number.

20993111 is a deficient number, since it is larger than the sum of its proper divisors (1).

20993111 is an equidigital number, since it uses as much as digits as its factorization.

20993111 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 486, while the sum is 26.

The square root of 20993111 is about 4581.8239817784. The cubic root of 20993111 is about 275.8622457217.

The spelling of 20993111 in words is "twenty million, nine hundred ninety-three thousand, one hundred eleven".