81945702 has 32 divisors (see below), whose sum is σ = 186341760. Its totient is φ = 26679240.

The previous prime is 81945671. The next prime is 81945709. The reversal of 81945702 is 20754918.

81945702 is a `hidden beast` number, since 81 + 9 + 4 + 570 + 2 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81945709) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15324 + ... + 19967.

It is an arithmetic number, because the mean of its divisors is an integer number (5823180).

Almost surely, 2^81945702 is an apocalyptic number.

81945702 is an abundant number, since it is smaller than the sum of its proper divisors (104396058).

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

81945702 is a wasteful number, since it uses less digits than its factorization.

81945702 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35345 (or 35339 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The square root of 81945702 is about 9052.3865361572. The cubic root of 81945702 is about 434.3522344538.

The spelling of 81945702 in words is "eighty-one million, nine hundred forty-five thousand, seven hundred two".