81700275 has 24 divisors (see below), whose sum is σ = 135437760. Its totient is φ = 43457440.

The previous prime is 81700271. The next prime is 81700277. The reversal of 81700275 is 57200718.

It is a happy number.

It is not a de Polignac number, because 81700275 - 2² = 81700271 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81700271) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 31996 + ... + 34454.

It is an arithmetic number, because the mean of its divisors is an integer number (5643240).

Almost surely, 2^81700275 is an apocalyptic number.

81700275 is a deficient number, since it is larger than the sum of its proper divisors (53737485).

81700275 is a wasteful number, since it uses less digits than its factorization.

81700275 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2915 (or 2910 counting only the distinct ones).

The product of its (nonzero) digits is 3920, while the sum is 30.

The square root of 81700275 is about 9038.8204429560. The cubic root of 81700275 is about 433.9181731806.

The spelling of 81700275 in words is "eighty-one million, seven hundred thousand, two hundred seventy-five".