25531001081 has 16 divisors (see below), whose sum is σ = 28500091200. Its totient is φ = 22728895488.

The previous prime is 25531001059. The next prime is 25531001099. The reversal of 25531001081 is 18010013552.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 25531001081 - 2⁶ = 25531001017 is a prime.

It is a super-2 number, since 2×25531001081² (a number of 22 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 25531001081.

It is not an unprimeable number, because it can be changed into a prime (25531001981) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 146225 + ... + 269153.

It is an arithmetic number, because the mean of its divisors is an integer number (1781255700).

Almost surely, 2^25531001081 is an apocalyptic number.

It is an amenable number.

25531001081 is a deficient number, since it is larger than the sum of its proper divisors (2969090119).

25531001081 is a wasteful number, since it uses less digits than its factorization.

25531001081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 123608.

The product of its (nonzero) digits is 1200, while the sum is 26.

The spelling of 25531001081 in words is "twenty-five billion, five hundred thirty-one million, one thousand, eighty-one".