221510973 has 4 divisors (see below), whose sum is σ = 295347968. Its totient is φ = 147673980.

The previous prime is 221510959. The next prime is 221510977. The reversal of 221510973 is 379015122.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 221510973 - 2⁵ = 221510941 is a prime.

It is a super-2 number, since 2×221510973² = 98134222318813458, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 221510973.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221510977) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 36918493 + ... + 36918498.

It is an arithmetic number, because the mean of its divisors is an integer number (73836992).

Almost surely, 2^221510973 is an apocalyptic number.

It is an amenable number.

221510973 is a deficient number, since it is larger than the sum of its proper divisors (73836995).

221510973 is an equidigital number, since it uses as much as digits as its factorization.

221510973 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73836994.

The product of its (nonzero) digits is 3780, while the sum is 30.

The square root of 221510973 is about 14883.2447067163. The cubic root of 221510973 is about 605.0599608172.

The spelling of 221510973 in words is "two hundred twenty-one million, five hundred ten thousand, nine hundred seventy-three".