15990425432809 has 9 divisors (see below), whose sum is σ = 16715985114199. Its totient is φ = 15295101570760.

The previous prime is 15990425432803. The next prime is 15990425432837. The reversal of 15990425432809 is 90823452409951.

The square root of 15990425432809 is 3998803.

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

15990425432809 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., 12842568824409 + 3147856608400 = 3583653^2 + 1774220^2 .

It is not a de Polignac number, because 15990425432809 - 2¹⁵ = 15990425400041 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15990425432803) 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, 91885539 + ... + 92059399.

Almost surely, 2^{15990425432809} is an apocalyptic number.

15990425432809 is the 3998803-rd square number.

15990425432809 is the 1999402-nd centered octagonal number.

It is an amenable number.

15990425432809 is a deficient number, since it is larger than the sum of its proper divisors (725559681390).

15990425432809 is an frugal number, since it uses more digits than its factorization.

15990425432809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 347768 (or 173884 counting only the distinct ones).

The product of its (nonzero) digits is 27993600, while the sum is 61.

The spelling of 15990425432809 in words is "fifteen trillion, nine hundred ninety billion, four hundred twenty-five million, four hundred thirty-two thousand, eight hundred nine".