21913711 has 2 divisors, whose sum is σ = 21913712. Its totient is φ = 21913710.

The previous prime is 21913709. The next prime is 21913729. The reversal of 21913711 is 11731912.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21913711 - 2¹ = 21913709 is a prime.

It is a super-3 number, since 3×21913711³ (a number of 23 digits) contains 333 as substring.

Together with 21913709, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21913741) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10956855 + 10956856.

It is an arithmetic number, because the mean of its divisors is an integer number (10956856).

Almost surely, 2^21913711 is an apocalyptic number.

21913711 is the 2094-th centered decagonal number.

21913711 is a deficient number, since it is larger than the sum of its proper divisors (1).

21913711 is an equidigital number, since it uses as much as digits as its factorization.

21913711 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 378, while the sum is 25.

The square root of 21913711 is about 4681.2082841933. The cubic root of 21913711 is about 279.8371118920.

The spelling of 21913711 in words is "twenty-one million, nine hundred thirteen thousand, seven hundred eleven".