99987971 has 8 divisors (see below), whose sum is σ = 103425504. Its totient is φ = 96598080.

The previous prime is 99987961. The next prime is 99987973. The reversal of 99987971 is 17978999.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 99987971 - 2⁶ = 99987907 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 99987971.

It is not an unprimeable number, because it can be changed into a prime (99987973) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7616 + ... + 16061.

It is an arithmetic number, because the mean of its divisors is an integer number (12928188).

Almost surely, 2^99987971 is an apocalyptic number.

99987971 is a deficient number, since it is larger than the sum of its proper divisors (3437533).

99987971 is a wasteful number, since it uses less digits than its factorization.

99987971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23821.

The product of its digits is 2571912, while the sum is 59.

The square root of 99987971 is about 9999.3985319118. The cubic root of 99987971 is about 464.1402713910.

The spelling of 99987971 in words is "ninety-nine million, nine hundred eighty-seven thousand, nine hundred seventy-one".