99981715 has 4 divisors (see below), whose sum is σ = 119978064. Its totient is φ = 79985368.

The previous prime is 99981701. The next prime is 99981757. The reversal of 99981715 is 51718999.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-99981715 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian 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, 9998167 + ... + 9998176.

It is an arithmetic number, because the mean of its divisors is an integer number (29994516).

Almost surely, 2^99981715 is an apocalyptic number.

99981715 is a deficient number, since it is larger than the sum of its proper divisors (19996349).

99981715 is a wasteful number, since it uses less digits than its factorization.

99981715 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19996348.

The product of its digits is 204120, while the sum is 49.

The square root of 99981715 is about 9999.0857082035. The cubic root of 99981715 is about 464.1305911529.

The spelling of 99981715 in words is "ninety-nine million, nine hundred eighty-one thousand, seven hundred fifteen".