21230331979 has 2 divisors, whose sum is σ = 21230331980. Its totient is φ = 21230331978.

The previous prime is 21230331943. The next prime is 21230332027. The reversal of 21230331979 is 97913303212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21230331979 - 2³¹ = 19082848331 is a prime.

It is not a weakly prime, because it can be changed into another prime (21230331379) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10615165989 + 10615165990.

It is an arithmetic number, because the mean of its divisors is an integer number (10615165990).

Almost surely, 2^21230331979 is an apocalyptic number.

21230331979 is a deficient number, since it is larger than the sum of its proper divisors (1).

21230331979 is an equidigital number, since it uses as much as digits as its factorization.

21230331979 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 61236, while the sum is 40.

The spelling of 21230331979 in words is "twenty-one billion, two hundred thirty million, three hundred thirty-one thousand, nine hundred seventy-nine".