221657091 has 8 divisors (see below), whose sum is σ = 296022720. Its totient is φ = 147531432.

The previous prime is 221657087. The next prime is 221657113. The reversal of 221657091 is 190756122.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 221657091 - 2² = 221657087 is a prime.

It is not an unprimeable number, because it can be changed into a prime (221652091) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 57825 + ... + 61538.

It is an arithmetic number, because the mean of its divisors is an integer number (37002840).

Almost surely, 2^221657091 is an apocalyptic number.

221657091 is a deficient number, since it is larger than the sum of its proper divisors (74365629).

221657091 is a wasteful number, since it uses less digits than its factorization.

221657091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 119985.

The product of its (nonzero) digits is 7560, while the sum is 33.

The square root of 221657091 is about 14888.1527060949. The cubic root of 221657091 is about 605.1929726158.

The spelling of 221657091 in words is "two hundred twenty-one million, six hundred fifty-seven thousand, ninety-one".