99405987 has 32 divisors (see below), whose sum is σ = 144986112. Its totient is φ = 60340224.

The previous prime is 99405947. The next prime is 99406009. The reversal of 99405987 is 78950499.

It is a happy number.

It is not a de Polignac number, because 99405987 - 2¹¹ = 99403939 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is not an unprimeable number, because it can be changed into a prime (99405907) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 270678 + ... + 271044.

It is an arithmetic number, because the mean of its divisors is an integer number (4530816).

Almost surely, 2^99405987 is an apocalyptic number.

99405987 is a deficient number, since it is larger than the sum of its proper divisors (45580125).

99405987 is a wasteful number, since it uses less digits than its factorization.

99405987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 547.

The product of its (nonzero) digits is 816480, while the sum is 51.

The square root of 99405987 is about 9970.2551120821. The cubic root of 99405987 is about 463.2380028613.

The spelling of 99405987 in words is "ninety-nine million, four hundred five thousand, nine hundred eighty-seven".