81075629925 has 36 divisors (see below), whose sum is σ = 145233828324. Its totient is φ = 43234867200.

The previous prime is 81075629897. The next prime is 81075629927. The reversal of 81075629925 is 52992657018.

81075629925 is a `hidden beast` number, since 8 + 1 + 0 + 7 + 5 + 629 + 9 + 2 + 5 = 666.

It can be written as a sum of positive squares in 6 ways, for example, as 5463279396 + 75612350529 = 73914^2 + 274977^2 .

It is not a de Polignac number, because 81075629925 - 2⁵ = 81075629893 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81075629927) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 2273029 + ... + 2308421.

It is an arithmetic number, because the mean of its divisors is an integer number (4034273009).

Almost surely, 2^81075629925 is an apocalyptic number.

It is an amenable number.

81075629925 is a deficient number, since it is larger than the sum of its proper divisors (64158198399).

81075629925 is a wasteful number, since it uses less digits than its factorization.

81075629925 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45590 (or 45582 counting only the distinct ones).

The product of its (nonzero) digits is 2721600, while the sum is 54.

The spelling of 81075629925 in words is "eighty-one billion, seventy-five million, six hundred twenty-nine thousand, nine hundred twenty-five".