121569979439 has 4 divisors (see below), whose sum is σ = 121578013200. Its totient is φ = 121561945680.

The previous prime is 121569979397. The next prime is 121569979451. The reversal of 121569979439 is 934979965121.

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

It is a cyclic number.

It is not a de Polignac number, because 121569979439 - 2¹² = 121569975343 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121569979459) 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, 3994139 + ... + 4024460.

It is an arithmetic number, because the mean of its divisors is an integer number (30394503300).

Almost surely, 2^121569979439 is an apocalyptic number.

121569979439 is a deficient number, since it is larger than the sum of its proper divisors (8033761).

121569979439 is an equidigital number, since it uses as much as digits as its factorization.

121569979439 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8033760.

The product of its digits is 33067440, while the sum is 65.

The spelling of 121569979439 in words is "one hundred twenty-one billion, five hundred sixty-nine million, nine hundred seventy-nine thousand, four hundred thirty-nine".