221920715 has 8 divisors (see below), whose sum is σ = 267319008. Its totient is φ = 176860480.

The previous prime is 221920711. The next prime is 221920729. The reversal of 221920715 is 517029122.

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

It is not a de Polignac number, because 221920715 - 2² = 221920711 is a prime.

It is a super-2 number, since 2×221920715² = 98497607492222450, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221920711) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 83066 + ... + 85695.

It is an arithmetic number, because the mean of its divisors is an integer number (33414876).

Almost surely, 2^221920715 is an apocalyptic number.

221920715 is a deficient number, since it is larger than the sum of its proper divisors (45398293).

221920715 is a wasteful number, since it uses less digits than its factorization.

221920715 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 169029.

The product of its (nonzero) digits is 2520, while the sum is 29.

The square root of 221920715 is about 14897.0035577629. The cubic root of 221920715 is about 605.4328028015.

Adding to 221920715 its reverse (517029122), we get a palindrome (738949837).

The spelling of 221920715 in words is "two hundred twenty-one million, nine hundred twenty thousand, seven hundred fifteen".