99870978 has 8 divisors (see below), whose sum is σ = 199741968. Its totient is φ = 33290324.

The previous prime is 99870977. The next prime is 99871007. The reversal of 99870978 is 87907899.

It is a happy number.

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

99870978 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (99870977) 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, 8322576 + ... + 8322587.

It is an arithmetic number, because the mean of its divisors is an integer number (24967746).

Almost surely, 2^99870978 is an apocalyptic number.

99870978 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

99870978 is a wasteful number, since it uses less digits than its factorization.

99870978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16645168.

The product of its (nonzero) digits is 2286144, while the sum is 57.

The square root of 99870978 is about 9993.5468178220. The cubic root of 99870978 is about 463.9591750893.

The spelling of 99870978 in words is "ninety-nine million, eight hundred seventy thousand, nine hundred seventy-eight".