18929632225 has 27 divisors (see below), whose sum is σ = 27311976531. Its totient is φ = 12977017200.

The previous prime is 18929632223. The next prime is 18929632229. The reversal of 18929632225 is 52223692981.

It is a happy number.

The square root of 18929632225 is 137585.

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., 6814667601 + 12114964624 = 82551^2 + 110068^2 .

It is not a de Polignac number, because 18929632225 - 2¹ = 18929632223 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (49).

It is not an unprimeable number, because it can be changed into a prime (18929632223) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 4813510 + ... + 4817440.

Almost surely, 2^18929632225 is an apocalyptic number.

18929632225 is the 137585-th square number.

18929632225 is the 68793-rd centered octagonal number.

It is an amenable number.

18929632225 is a deficient number, since it is larger than the sum of its proper divisors (8382344306).

18929632225 is an frugal number, since it uses more digits than its factorization.

18929632225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7886 (or 3943 counting only the distinct ones).

The product of its digits is 933120, while the sum is 49.

Multiplying 18929632225 by its sum of digits (49), we get a square (927551979025 = 963095²).

18929632225 divided by its sum of digits (49) gives a square (386319025 = 19655²).

The spelling of 18929632225 in words is "eighteen billion, nine hundred twenty-nine million, six hundred thirty-two thousand, two hundred twenty-five".