15963564409 has 9 divisors (see below), whose sum is σ = 17287768623. Its totient is φ = 14734081752.

The previous prime is 15963564403. The next prime is 15963564439. The reversal of 15963564409 is 90446536951.

It is a happy number.

The square root of 15963564409 is 126347.

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

It can be written as a sum of positive squares in only one way, i.e., 2361474025 + 13602090384 = 48595^2 + 116628^2 .

It is not a de Polignac number, because 15963564409 - 2⁵ = 15963564377 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15963564403) 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, 1637652 + ... + 1647370.

Almost surely, 2^15963564409 is an apocalyptic number.

15963564409 is the 126347-th square number.

15963564409 is the 63174-th centered octagonal number.

It is an amenable number.

15963564409 is a deficient number, since it is larger than the sum of its proper divisors (1324204214).

15963564409 is an frugal number, since it uses more digits than its factorization.

15963564409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19464 (or 9732 counting only the distinct ones).

The product of its (nonzero) digits is 3499200, while the sum is 52.

The spelling of 15963564409 in words is "fifteen billion, nine hundred sixty-three million, five hundred sixty-four thousand, four hundred nine".