990615458561 has 4 divisors (see below), whose sum is σ = 992516832324. Its totient is φ = 988714084800.

The previous prime is 990615458551. The next prime is 990615458603. The reversal of 990615458561 is 165854516099.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 198052590961 + 792562867600 = 445031^2 + 890260^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-990615458561 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 990615458561.

It is not an unprimeable number, because it can be changed into a prime (990615458551) 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, 950686100 + ... + 950687141.

It is an arithmetic number, because the mean of its divisors is an integer number (248129208081).

Almost surely, 2^990615458561 is an apocalyptic number.

It is an amenable number.

990615458561 is a deficient number, since it is larger than the sum of its proper divisors (1901373763).

990615458561 is a wasteful number, since it uses less digits than its factorization.

990615458561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1901373762.

The product of its (nonzero) digits is 11664000, while the sum is 59.

The spelling of 990615458561 in words is "nine hundred ninety billion, six hundred fifteen million, four hundred fifty-eight thousand, five hundred sixty-one".