21421711 has 2 divisors, whose sum is σ = 21421712. Its totient is φ = 21421710.

The previous prime is 21421703. The next prime is 21421727. The reversal of 21421711 is 11712412.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21421711 - 2³ = 21421703 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21422711) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10710855 + 10710856.

It is an arithmetic number, because the mean of its divisors is an integer number (10710856).

Almost surely, 2^21421711 is an apocalyptic number.

21421711 is a deficient number, since it is larger than the sum of its proper divisors (1).

21421711 is an equidigital number, since it uses as much as digits as its factorization.

21421711 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 112, while the sum is 19.

The square root of 21421711 is about 4628.3594285665. The cubic root of 21421711 is about 277.7269674117.

The spelling of 21421711 in words is "twenty-one million, four hundred twenty-one thousand, seven hundred eleven".