25156814881 has 9 divisors (see below), whose sum is σ = 27653623473. Its totient is φ = 22868245620.

The previous prime is 25156814843. The next prime is 25156814911. The reversal of 25156814881 is 18841865152.

It is a happy number.

The square root of 25156814881 is 158609.

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

It is not a de Polignac number, because 25156814881 - 2¹⁷ = 25156683809 is a prime.

It is a super-2 number, since 2×25156814881² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25156814801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 1737490 + ... + 1751908.

Almost surely, 2^25156814881 is an apocalyptic number.

25156814881 is the 158609-th square number.

25156814881 is the 79305-th centered octagonal number.

It is an amenable number.

25156814881 is a deficient number, since it is larger than the sum of its proper divisors (2496808592).

25156814881 is an frugal number, since it uses more digits than its factorization.

25156814881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28860 (or 14430 counting only the distinct ones).

The product of its digits is 614400, while the sum is 49.

Multiplying 25156814881 by its sum of digits (49), we get a square (1232683929169 = 1110263²).

The spelling of 25156814881 in words is "twenty-five billion, one hundred fifty-six million, eight hundred fourteen thousand, eight hundred eighty-one".