81200536 has 16 divisors (see below), whose sum is σ = 152346600. Its totient is φ = 40574784.

The previous prime is 81200527. The next prime is 81200573. The reversal of 81200536 is 63500218.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 81200536.

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, 23700 + ... + 26908.

Almost surely, 2^81200536 is an apocalyptic number.

It is an amenable number.

81200536 is a deficient number, since it is larger than the sum of its proper divisors (71146064).

81200536 is a wasteful number, since it uses less digits than its factorization.

81200536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6378 (or 6374 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 81200536 is about 9011.1340018890. The cubic root of 81200536 is about 433.0316422108.

The spelling of 81200536 in words is "eighty-one million, two hundred thousand, five hundred thirty-six".