15221656220 has 48 divisors (see below), whose sum is σ = 33411571200. Its totient is φ = 5814110016.

The previous prime is 15221656217. The next prime is 15221656223. The reversal of 15221656220 is 2265612251.

It is an interprime number because it is at equal distance from previous prime (15221656217) and next prime (15221656223).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15221656223) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 247919 + ... + 303161.

It is an arithmetic number, because the mean of its divisors is an integer number (696074400).

Almost surely, 2^15221656220 is an apocalyptic number.

15221656220 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 15221656220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (16705785600).

15221656220 is an abundant number, since it is smaller than the sum of its proper divisors (18189914980).

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

15221656220 is a wasteful number, since it uses less digits than its factorization.

15221656220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55874 (or 55872 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 32.

The spelling of 15221656220 in words is "fifteen billion, two hundred twenty-one million, six hundred fifty-six thousand, two hundred twenty".