21101229979 has 2 divisors, whose sum is σ = 21101229980. Its totient is φ = 21101229978.

The previous prime is 21101229953. The next prime is 21101230013. The reversal of 21101229979 is 97992210112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21101229979 - 2¹³ = 21101221787 is a prime.

It is not a weakly prime, because it can be changed into another prime (21101209979) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10550614989 + 10550614990.

It is an arithmetic number, because the mean of its divisors is an integer number (10550614990).

Almost surely, 2^21101229979 is an apocalyptic number.

21101229979 is a deficient number, since it is larger than the sum of its proper divisors (1).

21101229979 is an equidigital number, since it uses as much as digits as its factorization.

21101229979 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 40824, while the sum is 43.

The spelling of 21101229979 in words is "twenty-one billion, one hundred one million, two hundred twenty-nine thousand, nine hundred seventy-nine".