15506733503881 has 9 divisors (see below), whose sum is σ = 15541064638023. Its totient is φ = 15472478068440.

The previous prime is 15506733503867. The next prime is 15506733503897. The reversal of 15506733503881 is 18830533760551.

The square root of 15506733503881 is 3937859.

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

15506733503881 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., 14607233007481 + 899500496400 = 3821941^2 + 948420^2 .

It is not a de Polignac number, because 15506733503881 - 2¹³ = 15506733495689 is a prime.

It is a super-2 number, since 2×15506733503881² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15506733503581) 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, 1886230351 + ... + 1886238571.

Almost surely, 2^{15506733503881} is an apocalyptic number.

15506733503881 is the 3937859-th square number.

15506733503881 is the 1968930-th centered octagonal number.

It is an amenable number.

15506733503881 is a deficient number, since it is larger than the sum of its proper divisors (34331134142).

15506733503881 is an frugal number, since it uses more digits than its factorization.

15506733503881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17400 (or 8700 counting only the distinct ones).

The product of its (nonzero) digits is 9072000, while the sum is 55.

The spelling of 15506733503881 in words is "fifteen trillion, five hundred six billion, seven hundred thirty-three million, five hundred three thousand, eight hundred eighty-one".