221561375 has 32 divisors (see below), whose sum is σ = 332666880. Its totient is φ = 143920800.

The previous prime is 221561321. The next prime is 221561381. The reversal of 221561375 is 573165122.

221561375 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 221561375 - 2⁶ = 221561311 is a prime.

It is a super-3 number, since 3×221561375³ (a number of 26 digits) contains 333 as substring.

It is a congruent number.

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, 9962 + ... + 23288.

It is an arithmetic number, because the mean of its divisors is an integer number (10395840).

Almost surely, 2^221561375 is an apocalyptic number.

221561375 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

221561375 is a deficient number, since it is larger than the sum of its proper divisors (111105505).

221561375 is a wasteful number, since it uses less digits than its factorization.

221561375 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13368 (or 13358 counting only the distinct ones).

The product of its digits is 12600, while the sum is 32.

The square root of 221561375 is about 14884.9378567732. The cubic root of 221561375 is about 605.1058485656.

The spelling of 221561375 in words is "two hundred twenty-one million, five hundred sixty-one thousand, three hundred seventy-five".