20112912409 has 4 divisors (see below), whose sum is σ = 20139482404. Its totient is φ = 20086342416.

The previous prime is 20112912401. The next prime is 20112912431. The reversal of 20112912409 is 90421921102.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 12426006784 + 7686905625 = 111472^2 + 87675^2 .

It is a cyclic number.

It is not a de Polignac number, because 20112912409 - 2³ = 20112912401 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20112912401) 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, 13283862 + ... + 13285375.

It is an arithmetic number, because the mean of its divisors is an integer number (5034870601).

Almost surely, 2^20112912409 is an apocalyptic number.

It is an amenable number.

20112912409 is a deficient number, since it is larger than the sum of its proper divisors (26569995).

20112912409 is an equidigital number, since it uses as much as digits as its factorization.

20112912409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26569994.

The product of its (nonzero) digits is 2592, while the sum is 31.

The spelling of 20112912409 in words is "twenty billion, one hundred twelve million, nine hundred twelve thousand, four hundred nine".