99991290 has 64 divisors (see below), whose sum is σ = 275768064. Its totient is φ = 22729728.

The previous prime is 99991277. The next prime is 99991303. The reversal of 99991290 is 9219999.

It is an interprime number because it is at equal distance from previous prime (99991277) and next prime (99991303).

It is a Smith number, since the sum of its digits (48) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 40162 + ... + 42578.

It is an arithmetic number, because the mean of its divisors is an integer number (4308876).

Almost surely, 2^99991290 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 99991290, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (137884032).

99991290 is an abundant number, since it is smaller than the sum of its proper divisors (175776774).

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

99991290 is a wasteful number, since it uses less digits than its factorization.

99991290 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2631.

The product of its (nonzero) digits is 118098, while the sum is 48.

The square root of 99991290 is about 9999.5644905166. The cubic root of 99991290 is about 464.1454068904.

The spelling of 99991290 in words is "ninety-nine million, nine hundred ninety-one thousand, two hundred ninety".