15906506641 has 9 divisors (see below), whose sum is σ = 16477709521. Its totient is φ = 15354475024.

The previous prime is 15906506611. The next prime is 15906506647. The reversal of 15906506641 is 14660560951.

The square root of 15906506641 is 126121.

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

It can be written as a sum of positive squares in 4 ways, for example, as 5231484241 + 10675022400 = 72329^2 + 103320^2 .

It is not a de Polignac number, because 15906506641 - 2¹⁹ = 15905982353 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15906506647) 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, 3655335 + ... + 3659683.

Almost surely, 2^15906506641 is an apocalyptic number.

15906506641 is the 126121-st square number.

15906506641 is the 63061-st centered octagonal number.

It is an amenable number.

15906506641 is a deficient number, since it is larger than the sum of its proper divisors (571202880).

15906506641 is an frugal number, since it uses more digits than its factorization.

15906506641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8756 (or 4378 counting only the distinct ones).

The product of its (nonzero) digits is 194400, while the sum is 43.

The spelling of 15906506641 in words is "fifteen billion, nine hundred six million, five hundred six thousand, six hundred forty-one".