15597761881 has 15 divisors (see below), whose sum is σ = 16920426201. Its totient is φ = 14378451048.

The previous prime is 15597761863. The next prime is 15597761899. The reversal of 15597761881 is 18816779551.

The square root of 15597761881 is 124891.

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

It is an interprime number because it is at equal distance from previous prime (15597761863) and next prime (15597761899).

It can be written as a sum of positive squares in 2 ways, for example, as 7733619481 + 7864142400 = 87941^2 + 88680^2 .

It is not a de Polignac number, because 15597761881 - 2⁵ = 15597761849 is a prime.

It is a super-2 number, since 2×15597761881² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15597765881) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 21106210 + ... + 21106948.

Almost surely, 2^15597761881 is an apocalyptic number.

15597761881 is the 124891-st square number.

15597761881 is the 62446-th centered octagonal number.

It is an amenable number.

15597761881 is a deficient number, since it is larger than the sum of its proper divisors (1322664320).

15597761881 is an frugal number, since it uses more digits than its factorization.

15597761881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1530 (or 752 counting only the distinct ones).

The product of its digits is 4233600, while the sum is 58.

The spelling of 15597761881 in words is "fifteen billion, five hundred ninety-seven million, seven hundred sixty-one thousand, eight hundred eighty-one".