20434947979 has 2 divisors, whose sum is σ = 20434947980. Its totient is φ = 20434947978.

The previous prime is 20434947947. The next prime is 20434947989. The reversal of 20434947979 is 97974943402.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20434947979 - 2⁵ = 20434947947 is a prime.

It is not a weakly prime, because it can be changed into another prime (20434947989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10217473989 + 10217473990.

It is an arithmetic number, because the mean of its divisors is an integer number (10217473990).

Almost surely, 2^20434947979 is an apocalyptic number.

20434947979 is a deficient number, since it is larger than the sum of its proper divisors (1).

20434947979 is an equidigital number, since it uses as much as digits as its factorization.

20434947979 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13716864, while the sum is 58.

The spelling of 20434947979 in words is "twenty billion, four hundred thirty-four million, nine hundred forty-seven thousand, nine hundred seventy-nine".