221261556 has 24 divisors (see below), whose sum is σ = 516629344. Its totient is φ = 73703520.

The previous prime is 221261549. The next prime is 221261597. The reversal of 221261556 is 655162122.

221261556 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×221261556² = 97913352327082272, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14871 + ... + 25761.

Almost surely, 2^221261556 is an apocalyptic number.

It is an amenable number.

221261556 is an abundant number, since it is smaller than the sum of its proper divisors (295367788).

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

221261556 is a wasteful number, since it uses less digits than its factorization.

221261556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12591 (or 12589 counting only the distinct ones).

The product of its digits is 7200, while the sum is 30.

The square root of 221261556 is about 14874.8632262619. The cubic root of 221261556 is about 604.8327803227.

The spelling of 221261556 in words is "two hundred twenty-one million, two hundred sixty-one thousand, five hundred fifty-six".