21030679979 has 2 divisors, whose sum is σ = 21030679980. Its totient is φ = 21030679978.

The previous prime is 21030679973. The next prime is 21030680029. The reversal of 21030679979 is 97997603012.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21030679979 is a prime.

It is a super-2 number, since 2×21030679979² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21030679979.

It is not a weakly prime, because it can be changed into another prime (21030679973) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10515339989 + 10515339990.

It is an arithmetic number, because the mean of its divisors is an integer number (10515339990).

Almost surely, 2^21030679979 is an apocalyptic number.

21030679979 is a deficient number, since it is larger than the sum of its proper divisors (1).

21030679979 is an equidigital number, since it uses as much as digits as its factorization.

21030679979 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1285956, while the sum is 53.

The spelling of 21030679979 in words is "twenty-one billion, thirty million, six hundred seventy-nine thousand, nine hundred seventy-nine".