81249995 has 8 divisors (see below), whose sum is σ = 98039760. Its totient is φ = 64640160.

The previous prime is 81249979. The next prime is 81249997. The reversal of 81249995 is 59994218.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 81249995 - 2⁴ = 81249979 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81249997) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 43985 + ... + 45794.

It is an arithmetic number, because the mean of its divisors is an integer number (12254970).

Almost surely, 2^81249995 is an apocalyptic number.

81249995 is a deficient number, since it is larger than the sum of its proper divisors (16789765).

81249995 is a wasteful number, since it uses less digits than its factorization.

81249995 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89965.

The product of its digits is 233280, while the sum is 47.

The square root of 81249995 is about 9013.8779113099. The cubic root of 81249995 is about 433.1195437859.

The spelling of 81249995 in words is "eighty-one million, two hundred forty-nine thousand, nine hundred ninety-five".