15222720 has 112 divisors (see below), whose sum is σ = 49121568. Its totient is φ = 3993600.

The previous prime is 15222719. The next prime is 15222761. The reversal of 15222720 is 2722251.

It is a happy number.

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, 96882 + ... + 97038.

Almost surely, 2^15222720 is an apocalyptic number.

15222720 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 15222720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24560784).

15222720 is an abundant number, since it is smaller than the sum of its proper divisors (33898848).

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

15222720 is a wasteful number, since it uses less digits than its factorization.

15222720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 278 (or 268 counting only the distinct ones).

The product of its (nonzero) digits is 560, while the sum is 21.

The square root of 15222720 is about 3901.6304284235. The cubic root of 15222720 is about 247.8358261324.

Adding to 15222720 its reverse (2722251), we get a palindrome (17944971).

The spelling of 15222720 in words is "fifteen million, two hundred twenty-two thousand, seven hundred twenty".