81153725 has 12 divisors (see below), whose sum is σ = 102773184. Its totient is φ = 63540720.

The previous prime is 81153713. The next prime is 81153727. The reversal of 81153725 is 52735118.

It is not a de Polignac number, because 81153725 - 2²⁶ = 14044861 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81153691 and 81153700.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81153727) 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, 33359 + ... + 35708.

It is an arithmetic number, because the mean of its divisors is an integer number (8564432).

Almost surely, 2^81153725 is an apocalyptic number.

It is an amenable number.

81153725 is a deficient number, since it is larger than the sum of its proper divisors (21619459).

81153725 is a wasteful number, since it uses less digits than its factorization.

81153725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69124 (or 69119 counting only the distinct ones).

The product of its digits is 8400, while the sum is 32.

The square root of 81153725 is about 9008.5362295991. The cubic root of 81153725 is about 432.9484139396.

The spelling of 81153725 in words is "eighty-one million, one hundred fifty-three thousand, seven hundred twenty-five".