15503985225 has 45 divisors (see below), whose sum is σ = 28729122807. Its totient is φ = 8265803760.

The previous prime is 15503985179. The next prime is 15503985229. The reversal of 15503985225 is 52258930551.

It is a happy number.

The square root of 15503985225 is 124515.

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

15503985225 is a `hidden beast` number, since 1 + 5 + 503 + 98 + 52 + 2 + 5 = 666.

It can be written as a sum of positive squares in only one way, i.e., 5581434681 + 9922550544 = 74709^2 + 99612^2 .

It is a tau number, because it is divible by the number of its divisors (45).

It is not a de Polignac number, because 15503985225 - 2²⁵ = 15470430793 is a prime.

It is a super-3 number, since 3×15503985225³ (a number of 32 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Curzon number.

It is a zygodrome in base 3.

It is not an unprimeable number, because it can be changed into a prime (15503985229) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 5601792 + ... + 5604558.

Almost surely, 2^15503985225 is an apocalyptic number.

15503985225 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

15503985225 is the 124515-th square number.

15503985225 is the 62258-th centered octagonal number.

It is an amenable number.

15503985225 is a deficient number, since it is larger than the sum of its proper divisors (13225137582).

15503985225 is an frugal number, since it uses more digits than its factorization.

15503985225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5556 (or 2775 counting only the distinct ones).

The product of its (nonzero) digits is 540000, while the sum is 45.

The spelling of 15503985225 in words is "fifteen billion, five hundred three million, nine hundred eighty-five thousand, two hundred twenty-five".