9801990025 has 9 divisors (see below), whose sum is σ = 12155081493. Its totient is φ = 7841196000.

The previous prime is 9801989993. The next prime is 9801990073. The reversal of 9801990025 is 5200991089.

The square root of 9801990025 is 99005.

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

It can be written as a sum of positive squares in 4 ways, for example, as 6178431609 + 3623558416 = 78603^2 + 60196^2 .

It is not a de Polignac number, because 9801990025 - 2⁵ = 9801989993 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 485125 + ... + 504925.

Almost surely, 2^9801990025 is an apocalyptic number.

9801990025 is the 99005-th square number.

9801990025 is the 49503-rd centered octagonal number.

It is an amenable number.

9801990025 is a deficient number, since it is larger than the sum of its proper divisors (2353091468).

9801990025 is an frugal number, since it uses more digits than its factorization.

9801990025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39612 (or 19806 counting only the distinct ones).

The product of its (nonzero) digits is 58320, while the sum is 43.

The cubic root of 9801990025 is about 2140.1198017917.

It can be divided in two parts, 9801 and 990025, that multiplied together give a square (9703235025 = 98505²).

The spelling of 9801990025 in words is "nine billion, eight hundred one million, nine hundred ninety thousand, twenty-five".