221724065 has 16 divisors (see below), whose sum is σ = 271546560. Its totient is φ = 173749440.

The previous prime is 221724031. The next prime is 221724067. The reversal of 221724065 is 560427122.

It is a happy number.

It is not a de Polignac number, because 221724065 - 2⁶ = 221724001 is a prime.

It is a super-2 number, since 2×221724065² = 98323122000248450, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (221724067) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 92330 + ... + 94700.

It is an arithmetic number, because the mean of its divisors is an integer number (16971660).

Almost surely, 2^221724065 is an apocalyptic number.

It is an amenable number.

221724065 is a deficient number, since it is larger than the sum of its proper divisors (49822495).

221724065 is a wasteful number, since it uses less digits than its factorization.

221724065 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2752.

The product of its (nonzero) digits is 6720, while the sum is 29.

The square root of 221724065 is about 14890.4017742974. The cubic root of 221724065 is about 605.2539197787.

The spelling of 221724065 in words is "two hundred twenty-one million, seven hundred twenty-four thousand, sixty-five".