81700740 has 72 divisors (see below), whose sum is σ = 270361728. Its totient is φ = 19805760.

The previous prime is 81700721. The next prime is 81700747. The reversal of 81700740 is 4700718.

It is not an unprimeable number, because it can be changed into a prime (81700747) 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, 18652 + ... + 22611.

It is an arithmetic number, because the mean of its divisors is an integer number (3755024).

Almost surely, 2^81700740 is an apocalyptic number.

It is an amenable number.

81700740 is an abundant number, since it is smaller than the sum of its proper divisors (188660988).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81700740 is a wasteful number, since it uses less digits than its factorization.

81700740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41289 (or 41284 counting only the distinct ones).

The product of its (nonzero) digits is 1568, while the sum is 27.

The square root of 81700740 is about 9038.8461653023. The cubic root of 81700740 is about 433.9189963993.

The spelling of 81700740 in words is "eighty-one million, seven hundred thousand, seven hundred forty".