81735572 has 12 divisors (see below), whose sum is σ = 147969780. Its totient is φ = 39458496.

The previous prime is 81735571. The next prime is 81735607. The reversal of 81735572 is 27553718.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 55562116 + 26173456 = 7454^2 + 5116^2 .

It is a hoax number, since the sum of its digits (38) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81735571) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 352193 + ... + 352424.

It is an arithmetic number, because the mean of its divisors is an integer number (12330815).

Almost surely, 2^81735572 is an apocalyptic number.

It is an amenable number.

81735572 is a deficient number, since it is larger than the sum of its proper divisors (66234208).

81735572 is a wasteful number, since it uses less digits than its factorization.

81735572 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 704650 (or 704648 counting only the distinct ones).

The product of its digits is 58800, while the sum is 38.

The square root of 81735572 is about 9040.7727545824. The cubic root of 81735572 is about 433.9806527934.

The spelling of 81735572 in words is "eighty-one million, seven hundred thirty-five thousand, five hundred seventy-two".