81203715 has 40 divisors (see below), whose sum is σ = 149526960. Its totient is φ = 42130368.

The previous prime is 81203711. The next prime is 81203729. The reversal of 81203715 is 51730218.

It is not a de Polignac number, because 81203715 - 2² = 81203711 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (81203711) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 12276 + ... + 17694.

It is an arithmetic number, because the mean of its divisors is an integer number (3738174).

Almost surely, 2^81203715 is an apocalyptic number.

81203715 is a deficient number, since it is larger than the sum of its proper divisors (68323245).

81203715 is a wasteful number, since it uses less digits than its factorization.

81203715 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5473 (or 5464 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 27.

The square root of 81203715 is about 9011.3103930561. The cubic root of 81203715 is about 433.0372931982.

It can be divided in two parts, 81203 and 715, that added together give a palindrome (81918).

The spelling of 81203715 in words is "eighty-one million, two hundred three thousand, seven hundred fifteen".