221557248 has 320 divisors, whose sum is σ = 754237440. Its totient is φ = 63590400.

The previous prime is 221557211. The next prime is 221557267. The reversal of 221557248 is 842755122.

It is a happy number.

It is a harmonic number, since the harmonic mean of its divisors is an integer.

It is a super-2 number, since 2×221557248² = 98175228282667008, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4713961 + ... + 4714007.

It is an arithmetic number, because the mean of its divisors is an integer number (2356992).

Almost surely, 2^221557248 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221557248, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (377118720).

221557248 is an abundant number, since it is smaller than the sum of its proper divisors (532680192).

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

221557248 is a wasteful number, since it uses less digits than its factorization.

221557248 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116 (or 94 counting only the distinct ones).

The product of its digits is 44800, while the sum is 36.

The square root of 221557248 is about 14884.7992260561. The cubic root of 221557248 is about 605.1020914617.

It can be divided in two parts, 22155 and 7248, that added together give a triangular number (29403 = T₂₄₂).

The spelling of 221557248 in words is "two hundred twenty-one million, five hundred fifty-seven thousand, two hundred forty-eight".