15225720 has 64 divisors (see below), whose sum is σ = 45995040. Its totient is φ = 4032000.

The previous prime is 15225713. The next prime is 15225731. The reversal of 15225720 is 2752251.

15225720 = 251² + 252² + ... + 394².

15225720 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 21370 + ... + 22070.

Almost surely, 2^15225720 is an apocalyptic number.

15225720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 15225720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22997520).

15225720 is an abundant number, since it is smaller than the sum of its proper divisors (30769320).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

15225720 is a wasteful number, since it uses less digits than its factorization.

15225720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 896 (or 892 counting only the distinct ones).

The product of its (nonzero) digits is 1400, while the sum is 24.

The square root of 15225720 is about 3902.0148641439. The cubic root of 15225720 is about 247.8521057163.

Adding to 15225720 its reverse (2752251), we get a palindrome (17977971).

The spelling of 15225720 in words is "fifteen million, two hundred twenty-five thousand, seven hundred twenty".