990522521 has 4 divisors (see below), whose sum is σ = 1024678500. Its totient is φ = 956366544.

The previous prime is 990522517. The next prime is 990522529. The reversal of 990522521 is 125225099.

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 343583296 + 646939225 = 18536^2 + 25435^2 .

It is a cyclic number.

It is not a de Polignac number, because 990522521 - 2² = 990522517 is a prime.

It is a super-2 number, since 2×990522521² = 1962269729216390882, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (990522529) 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, 17077946 + ... + 17078003.

It is an arithmetic number, because the mean of its divisors is an integer number (256169625).

Almost surely, 2^990522521 is an apocalyptic number.

It is an amenable number.

990522521 is a deficient number, since it is larger than the sum of its proper divisors (34155979).

990522521 is a wasteful number, since it uses less digits than its factorization.

990522521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34155978.

The product of its (nonzero) digits is 16200, while the sum is 35.

The square root of 990522521 is about 31472.5677535215. The cubic root of 990522521 is about 996.8308071603.

The spelling of 990522521 in words is "nine hundred ninety million, five hundred twenty-two thousand, five hundred twenty-one".