81868532 has 12 divisors (see below), whose sum is σ = 151697700. Its totient is φ = 38526336.

The previous prime is 81868499. The next prime is 81868571. The reversal of 81868532 is 23586818.

It can be written as a sum of positive squares in 2 ways, for example, as 65189476 + 16679056 = 8074^2 + 4084^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 81868532.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 601907 + ... + 602042.

It is an arithmetic number, because the mean of its divisors is an integer number (12641475).

Almost surely, 2^81868532 is an apocalyptic number.

It is an amenable number.

81868532 is a deficient number, since it is larger than the sum of its proper divisors (69829168).

81868532 is a wasteful number, since it uses less digits than its factorization.

81868532 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1203970 (or 1203968 counting only the distinct ones).

The product of its digits is 92160, while the sum is 41.

The square root of 81868532 is about 9048.1231202941. The cubic root of 81868532 is about 434.2158454040.

The spelling of 81868532 in words is "eighty-one million, eight hundred sixty-eight thousand, five hundred thirty-two".