81597325 has 6 divisors (see below), whose sum is σ = 101180714. Its totient is φ = 65277840.

The previous prime is 81597323. The next prime is 81597349. The reversal of 81597325 is 52379518.

It can be written as a sum of positive squares in 3 ways, for example, as 6895876 + 74701449 = 2626^2 + 8643^2 .

It is not a de Polignac number, because 81597325 - 2¹ = 81597323 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81597323) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1631922 + ... + 1631971.

Almost surely, 2^81597325 is an apocalyptic number.

It is an amenable number.

81597325 is a deficient number, since it is larger than the sum of its proper divisors (19583389).

81597325 is a wasteful number, since it uses less digits than its factorization.

81597325 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3263903 (or 3263898 counting only the distinct ones).

The product of its digits is 75600, while the sum is 40.

The square root of 81597325 is about 9033.1237675568. The cubic root of 81597325 is about 433.7358373902.

The spelling of 81597325 in words is "eighty-one million, five hundred ninety-seven thousand, three hundred twenty-five".