21511079 has 2 divisors, whose sum is σ = 21511080. Its totient is φ = 21511078.

The previous prime is 21511031. The next prime is 21511093. The reversal of 21511079 is 97011512.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21511079 - 2¹² = 21506983 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 (21511979) 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, 10755539 + 10755540.

It is an arithmetic number, because the mean of its divisors is an integer number (10755540).

Almost surely, 2^21511079 is an apocalyptic number.

21511079 is a deficient number, since it is larger than the sum of its proper divisors (1).

21511079 is an equidigital number, since it uses as much as digits as its factorization.

21511079 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 630, while the sum is 26.

The square root of 21511079 is about 4638.0037731766. The cubic root of 21511079 is about 278.1126426189.

The spelling of 21511079 in words is "twenty-one million, five hundred eleven thousand, seventy-nine".