21942911 has 2 divisors, whose sum is σ = 21942912. Its totient is φ = 21942910.

The previous prime is 21942889. The next prime is 21942919. The reversal of 21942911 is 11924912.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21942911 is a 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 (21942919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10971455 + 10971456.

It is an arithmetic number, because the mean of its divisors is an integer number (10971456).

Almost surely, 2^21942911 is an apocalyptic number.

21942911 is a deficient number, since it is larger than the sum of its proper divisors (1).

21942911 is an equidigital number, since it uses as much as digits as its factorization.

21942911 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1296, while the sum is 29.

The square root of 21942911 is about 4684.3260988108. The cubic root of 21942911 is about 279.9613509579.

The spelling of 21942911 in words is "twenty-one million, nine hundred forty-two thousand, nine hundred eleven".