990123865 has 8 divisors (see below), whose sum is σ = 1193338440. Its totient is φ = 788639232.

The previous prime is 990123857. The next prime is 990123889. The reversal of 990123865 is 568321099.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 221503689 + 768620176 = 14883^2 + 27724^2 .

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 990123865 - 2³ = 990123857 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 431224 + ... + 433513.

It is an arithmetic number, because the mean of its divisors is an integer number (149167305).

Almost surely, 2^990123865 is an apocalyptic number.

It is an amenable number.

990123865 is a deficient number, since it is larger than the sum of its proper divisors (203214575).

990123865 is a wasteful number, since it uses less digits than its factorization.

990123865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 864971.

The product of its (nonzero) digits is 116640, while the sum is 43.

The square root of 990123865 is about 31466.2337276008. The cubic root of 990123865 is about 996.6970575825.

The spelling of 990123865 in words is "nine hundred ninety million, one hundred twenty-three thousand, eight hundred sixty-five".