21935479 has 2 divisors, whose sum is σ = 21935480. Its totient is φ = 21935478.

The previous prime is 21935471. The next prime is 21935509. The reversal of 21935479 is 97453912.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21935479 - 2³ = 21935471 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21935471) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10967739 + 10967740.

It is an arithmetic number, because the mean of its divisors is an integer number (10967740).

Almost surely, 2^21935479 is an apocalyptic number.

21935479 is a deficient number, since it is larger than the sum of its proper divisors (1).

21935479 is an equidigital number, since it uses as much as digits as its factorization.

21935479 is an evil number, because the sum of its binary digits is even.

The product of its digits is 68040, while the sum is 40.

The square root of 21935479 is about 4683.5327478304. The cubic root of 21935479 is about 279.9297400243.

The spelling of 21935479 in words is "twenty-one million, nine hundred thirty-five thousand, four hundred seventy-nine".