21411617979 has 4 divisors (see below), whose sum is σ = 28548823976. Its totient is φ = 14274411984.

The previous prime is 21411617977. The next prime is 21411617989. The reversal of 21411617979 is 97971611412.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 21411617979 - 2¹ = 21411617977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21411617977) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3568602994 + ... + 3568602999.

It is an arithmetic number, because the mean of its divisors is an integer number (7137205994).

Almost surely, 2^21411617979 is an apocalyptic number.

21411617979 is a deficient number, since it is larger than the sum of its proper divisors (7137205997).

21411617979 is an equidigital number, since it uses as much as digits as its factorization.

21411617979 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7137205996.

The product of its digits is 190512, while the sum is 48.

The spelling of 21411617979 in words is "twenty-one billion, four hundred eleven million, six hundred seventeen thousand, nine hundred seventy-nine".