81471525 has 24 divisors (see below), whose sum is σ = 141791520. Its totient is φ = 41163840.

The previous prime is 81471437. The next prime is 81471529. The reversal of 81471525 is 52517418.

It is not a de Polignac number, because 81471525 - 2¹² = 81467429 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81471529) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 27162 + ... + 30011.

It is an arithmetic number, because the mean of its divisors is an integer number (5907980).

Almost surely, 2^81471525 is an apocalyptic number.

It is an amenable number.

81471525 is a deficient number, since it is larger than the sum of its proper divisors (60319995).

81471525 is a wasteful number, since it uses less digits than its factorization.

81471525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57205 (or 57200 counting only the distinct ones).

The product of its digits is 11200, while the sum is 33.

The square root of 81471525 is about 9026.1578204682. The cubic root of 81471525 is about 433.5128234082.

The spelling of 81471525 in words is "eighty-one million, four hundred seventy-one thousand, five hundred twenty-five".