99981247 has 4 divisors (see below), whose sum is σ = 102419856. Its totient is φ = 97542640.

The previous prime is 99981229. The next prime is 99981251. The reversal of 99981247 is 74218999.

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

It is a cyclic number.

It is not a de Polignac number, because 99981247 - 2¹⁵ = 99948479 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 99981247.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99981227) 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, 1219243 + ... + 1219324.

It is an arithmetic number, because the mean of its divisors is an integer number (25604964).

Almost surely, 2^99981247 is an apocalyptic number.

99981247 is a deficient number, since it is larger than the sum of its proper divisors (2438609).

99981247 is a wasteful number, since it uses less digits than its factorization.

99981247 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2438608.

The product of its digits is 326592, while the sum is 49.

The square root of 99981247 is about 9999.0623060365. The cubic root of 99981247 is about 464.1298669756.

The spelling of 99981247 in words is "ninety-nine million, nine hundred eighty-one thousand, two hundred forty-seven".