15624999405409 has 9 divisors (see below), whose sum is σ = 15788129946771. Its totient is φ = 15463537464000.

The previous prime is 15624999405371. The next prime is 15624999405413. The reversal of 15624999405409 is 90450499942651.

The square root of 15624999405409 is 3952847.

It is a perfect power (a square), and thus also a powerful number.

15624999405409 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 7016220904225 + 8608778501184 = 2648815^2 + 2934072^2 .

It is not a de Polignac number, because 15624999405409 - 2⁹ = 15624999404897 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15624999405439) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 383405784 + ... + 383446534.

Almost surely, 2^{15624999405409} is an apocalyptic number.

15624999405409 is the 3952847-th square number.

15624999405409 is the 1976424-th centered octagonal number.

It is an amenable number.

15624999405409 is a deficient number, since it is larger than the sum of its proper divisors (163130541362).

15624999405409 is an frugal number, since it uses more digits than its factorization.

15624999405409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81696 (or 40848 counting only the distinct ones).

The product of its (nonzero) digits is 125971200, while the sum is 67.

The spelling of 15624999405409 in words is "fifteen trillion, six hundred twenty-four billion, nine hundred ninety-nine million, four hundred five thousand, four hundred nine".