221657090 has 8 divisors (see below), whose sum is σ = 398982780. Its totient is φ = 88662832.

The previous prime is 221657087. The next prime is 221657113. The reversal of 221657090 is 90756122.

It can be written as a sum of positive squares in 2 ways, for example, as 216590089 + 5067001 = 14717^2 + 2251^2 .

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11082845 + ... + 11082864.

Almost surely, 2^221657090 is an apocalyptic number.

221657090 is a deficient number, since it is larger than the sum of its proper divisors (177325690).

221657090 is a wasteful number, since it uses less digits than its factorization.

221657090 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22165716.

The product of its (nonzero) digits is 7560, while the sum is 32.

The square root of 221657090 is about 14888.1526725111. The cubic root of 221657090 is about 605.1929717057.

The spelling of 221657090 in words is "two hundred twenty-one million, six hundred fifty-seven thousand, ninety".