25544578531 has 2 divisors, whose sum is σ = 25544578532. Its totient is φ = 25544578530.

The previous prime is 25544578523. The next prime is 25544578561. The reversal of 25544578531 is 13587544552.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 25544578531 - 2³ = 25544578523 is a prime.

It is a super-2 number, since 2×25544578531² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (25544578561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12772289265 + 12772289266.

It is an arithmetic number, because the mean of its divisors is an integer number (12772289266).

Almost surely, 2^25544578531 is an apocalyptic number.

25544578531 is a deficient number, since it is larger than the sum of its proper divisors (1).

25544578531 is an equidigital number, since it uses as much as digits as its factorization.

25544578531 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3360000, while the sum is 49.

The spelling of 25544578531 in words is "twenty-five billion, five hundred forty-four million, five hundred seventy-eight thousand, five hundred thirty-one".