221151993 has 8 divisors (see below), whose sum is σ = 295104288. Its totient is φ = 147317184.

The previous prime is 221151977. The next prime is 221152013. The reversal of 221151993 is 399151122.

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

It is not a de Polignac number, because 221151993 - 2⁴ = 221151977 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (221151913) 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, 24880 + ... + 32577.

It is an arithmetic number, because the mean of its divisors is an integer number (36888036).

Almost surely, 2^221151993 is an apocalyptic number.

It is an amenable number.

221151993 is a deficient number, since it is larger than the sum of its proper divisors (73952295).

221151993 is a wasteful number, since it uses less digits than its factorization.

221151993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58743.

The product of its digits is 4860, while the sum is 33.

The square root of 221151993 is about 14871.1799464602. The cubic root of 221151993 is about 604.7329313234.

The spelling of 221151993 in words is "two hundred twenty-one million, one hundred fifty-one thousand, nine hundred ninety-three".