990138433249 has 9 divisors (see below), whose sum is σ = 1151801790321. Its totient is φ = 848684115300.

The previous prime is 990138433247. The next prime is 990138433253. The reversal of 990138433249 is 942334831099.

The square root of 990138433249 is 995057.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 990138433249 - 2¹ = 990138433247 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 990138433249.

It is not an unprimeable number, because it can be changed into a prime (990138433241) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 6894324 + ... + 7036474.

Almost surely, 2^990138433249 is an apocalyptic number.

990138433249 is the 995057-th square number.

990138433249 is the 497529-th centered octagonal number.

It is an amenable number.

990138433249 is a deficient number, since it is larger than the sum of its proper divisors (161663357072).

990138433249 is an frugal number, since it uses more digits than its factorization.

990138433249 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 284316 (or 142158 counting only the distinct ones).

The product of its (nonzero) digits is 5038848, while the sum is 55.

The spelling of 990138433249 in words is "nine hundred ninety billion, one hundred thirty-eight million, four hundred thirty-three thousand, two hundred forty-nine".