998422622521 has 9 divisors (see below), whose sum is σ = 1023410332399. Its totient is φ = 974030882800.

The previous prime is 998422622473. The next prime is 998422622567. The reversal of 998422622521 is 125226224899.

The square root of 998422622521 is 999211.

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

It can be written as a sum of positive squares in only one way, i.e., 48109596921 + 950313025600 = 219339^2 + 974840^2 .

It is a de Polignac number, because none of the positive numbers 2^k-998422622521 is a prime.

It is a super-2 number, since 2×998422622521² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (998422622591) 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, 40955466 + ... + 40979836.

Almost surely, 2^998422622521 is an apocalyptic number.

998422622521 is the 999211-st square number.

998422622521 is the 499606-th centered octagonal number.

It is an amenable number.

998422622521 is a deficient number, since it is larger than the sum of its proper divisors (24987709878).

998422622521 is an frugal number, since it uses more digits than its factorization.

998422622521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48824 (or 24412 counting only the distinct ones).

The product of its digits is 2488320, while the sum is 52.

The spelling of 998422622521 in words is "nine hundred ninety-eight billion, four hundred twenty-two million, six hundred twenty-two thousand, five hundred twenty-one".