21967579 has 2 divisors, whose sum is σ = 21967580. Its totient is φ = 21967578.

The previous prime is 21967549. The next prime is 21967619. The reversal of 21967579 is 97576912.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21967579 - 2²¹ = 19870427 is a prime.

It is not a weakly prime, because it can be changed into another prime (21967549) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10983789 + 10983790.

It is an arithmetic number, because the mean of its divisors is an integer number (10983790).

Almost surely, 2^21967579 is an apocalyptic number.

21967579 is a deficient number, since it is larger than the sum of its proper divisors (1).

21967579 is an equidigital number, since it uses as much as digits as its factorization.

21967579 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 238140, while the sum is 46.

The square root of 21967579 is about 4686.9583953775. The cubic root of 21967579 is about 280.0662215819.

The spelling of 21967579 in words is "twenty-one million, nine hundred sixty-seven thousand, five hundred seventy-nine".