21221031079 has 2 divisors, whose sum is σ = 21221031080. Its totient is φ = 21221031078.

The previous prime is 21221031047. The next prime is 21221031127. The reversal of 21221031079 is 97013012212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21221031079 - 2⁵ = 21221031047 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21221035079) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610515539 + 10610515540.

It is an arithmetic number, because the mean of its divisors is an integer number (10610515540).

Almost surely, 2^21221031079 is an apocalyptic number.

21221031079 is a deficient number, since it is larger than the sum of its proper divisors (1).

21221031079 is an equidigital number, since it uses as much as digits as its factorization.

21221031079 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1512, while the sum is 28.

The spelling of 21221031079 in words is "twenty-one billion, two hundred twenty-one million, thirty-one thousand, seventy-nine".