81061625 has 16 divisors (see below), whose sum is σ = 102685440. Its totient is φ = 63874800.

The previous prime is 81061553. The next prime is 81061681. The reversal of 81061625 is 52616018.

It is a happy number.

It is not a de Polignac number, because 81061625 - 2¹⁶ = 80996089 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3536 + ... + 13214.

It is an arithmetic number, because the mean of its divisors is an integer number (6417840).

Almost surely, 2^81061625 is an apocalyptic number.

It is an amenable number.

81061625 is a deficient number, since it is larger than the sum of its proper divisors (21623815).

81061625 is an equidigital number, since it uses as much as digits as its factorization.

81061625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9761 (or 9751 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 29.

The square root of 81061625 is about 9003.4229601858. The cubic root of 81061625 is about 432.7845699806.

The spelling of 81061625 in words is "eighty-one million, sixty-one thousand, six hundred twenty-five".