19955800225 has 27 divisors (see below), whose sum is σ = 26133691827. Its totient is φ = 15114224880.

The previous prime is 19955800213. The next prime is 19955800231. The reversal of 19955800225 is 52200855991.

It is a happy number.

The square root of 19955800225 is 141265.

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., 7184088081 + 12771712144 = 84759^2 + 113012^2 .

It is not a de Polignac number, because 19955800225 - 2¹⁵ = 19955767457 is a prime.

It is a super-2 number, since 2×19955800225² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 13419432 + ... + 13420918.

Almost surely, 2^19955800225 is an apocalyptic number.

19955800225 is the 141265-th square number.

19955800225 is the 70633-rd centered octagonal number.

It is an amenable number.

19955800225 is a deficient number, since it is larger than the sum of its proper divisors (6177891602).

19955800225 is an frugal number, since it uses more digits than its factorization.

19955800225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3022 (or 1511 counting only the distinct ones).

The product of its (nonzero) digits is 324000, while the sum is 46.

The spelling of 19955800225 in words is "nineteen billion, nine hundred fifty-five million, eight hundred thousand, two hundred twenty-five".