15697721341225 has 243 divisors, whose sum is σ = 25612654799109. Its totient is φ = 9508884000000.

The previous prime is 15697721341217. The next prime is 15697721341229. The reversal of 15697721341225 is 52214312779651.

The square root of 15697721341225 is 3962035.

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

15697721341225 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 6607423981081 + 9090297360144 = 2570491^2 + 3015012^2 .

It is not a de Polignac number, because 15697721341225 - 2³ = 15697721341217 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (55).

Its product of digits (6350400) is a multiple of the sum of its prime divisors (315).

It is not an unprimeable number, because it can be changed into a prime (15697721341229) by changing a digit.

It is a polite number, since it can be written in 242 ways as a sum of consecutive naturals, for example, 62540722350 + ... + 62540722600.

Almost surely, 2^{15697721341225} is an apocalyptic number.

15697721341225 is the 3962035-th square number.

15697721341225 is the 1981018-th centered octagonal number.

It is an amenable number.

15697721341225 is a deficient number, since it is larger than the sum of its proper divisors (9914933457884).

15697721341225 is an equidigital number, since it uses as much as digits as its factorization.

15697721341225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 630 (or 315 counting only the distinct ones).

The product of its digits is 6350400, while the sum is 55.

The spelling of 15697721341225 in words is "fifteen trillion, six hundred ninety-seven billion, seven hundred twenty-one million, three hundred forty-one thousand, two hundred twenty-five".