989998621 has 8 divisors (see below), whose sum is σ = 1048861440. Its totient is φ = 931205568.

The previous prime is 989998619. The next prime is 989998627. The reversal of 989998621 is 126899989.

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 989998621 - 2¹ = 989998619 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 989998621.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (989998627) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13350 + ... + 46456.

It is an arithmetic number, because the mean of its divisors is an integer number (131107680).

Almost surely, 2^989998621 is an apocalyptic number.

It is an amenable number.

989998621 is a deficient number, since it is larger than the sum of its proper divisors (58862819).

989998621 is a wasteful number, since it uses less digits than its factorization.

989998621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34883.

The product of its digits is 5038848, while the sum is 61.

The square root of 989998621 is about 31464.2435313484. The cubic root of 989998621 is about 996.6550306555.

The spelling of 989998621 in words is "nine hundred eighty-nine million, nine hundred ninety-eight thousand, six hundred twenty-one".