21430441979 has 2 divisors, whose sum is σ = 21430441980. Its totient is φ = 21430441978.

The previous prime is 21430441957. The next prime is 21430442009. The reversal of 21430441979 is 97914403412.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21430441979 is a prime.

It is not a weakly prime, because it can be changed into another prime (21430411979) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10715220989 + 10715220990.

It is an arithmetic number, because the mean of its divisors is an integer number (10715220990).

Almost surely, 2^21430441979 is an apocalyptic number.

21430441979 is a deficient number, since it is larger than the sum of its proper divisors (1).

21430441979 is an equidigital number, since it uses as much as digits as its factorization.

21430441979 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 217728, while the sum is 44.

The spelling of 21430441979 in words is "twenty-one billion, four hundred thirty million, four hundred forty-one thousand, nine hundred seventy-nine".