81946525 has 12 divisors (see below), whose sum is σ = 106962400. Its totient is φ = 62106480.

The previous prime is 81946523. The next prime is 81946531. The reversal of 81946525 is 52564918.

It is not a de Polignac number, because 81946525 - 2¹ = 81946523 is a prime.

It is a hoax number, since the sum of its digits (40) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81946523) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 85785 + ... + 86734.

Almost surely, 2^81946525 is an apocalyptic number.

It is an amenable number.

81946525 is a deficient number, since it is larger than the sum of its proper divisors (25015875).

81946525 is a wasteful number, since it uses less digits than its factorization.

81946525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 172548 (or 172543 counting only the distinct ones).

The product of its digits is 86400, while the sum is 40.

The square root of 81946525 is about 9052.4319936689. The cubic root of 81946525 is about 434.3536885495.

The spelling of 81946525 in words is "eighty-one million, nine hundred forty-six thousand, five hundred twenty-five".