221491375 has 16 divisors (see below), whose sum is σ = 315911232. Its totient is φ = 151879200.

The previous prime is 221491367. The next prime is 221491397. The reversal of 221491375 is 573194122.

It is a happy number.

It is not a de Polignac number, because 221491375 - 2³ = 221491367 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 221491375.

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, 125692 + ... + 127441.

It is an arithmetic number, because the mean of its divisors is an integer number (19744452).

Almost surely, 2^221491375 is an apocalyptic number.

221491375 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

221491375 is a deficient number, since it is larger than the sum of its proper divisors (94419857).

221491375 is an equidigital number, since it uses as much as digits as its factorization.

221491375 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 253155 (or 253145 counting only the distinct ones).

The product of its digits is 15120, while the sum is 34.

The square root of 221491375 is about 14882.5863007745. The cubic root of 221491375 is about 605.0421162312.

The spelling of 221491375 in words is "two hundred twenty-one million, four hundred ninety-one thousand, three hundred seventy-five".