221024399 has 16 divisors (see below), whose sum is σ = 235599840. Its totient is φ = 206976000.

The previous prime is 221024387. The next prime is 221024413. The reversal of 221024399 is 993420122.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221024399 is a prime.

It is a super-2 number, since 2×221024399² = 97703569906622402, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221024329) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 250439 + ... + 251319.

It is an arithmetic number, because the mean of its divisors is an integer number (14724990).

Almost surely, 2^221024399 is an apocalyptic number.

221024399 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

221024399 is a deficient number, since it is larger than the sum of its proper divisors (14575441).

221024399 is a wasteful number, since it uses less digits than its factorization.

221024399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1162.

The product of its (nonzero) digits is 7776, while the sum is 32.

The square root of 221024399 is about 14866.8893518449. The cubic root of 221024399 is about 604.6166084021.

The spelling of 221024399 in words is "two hundred twenty-one million, twenty-four thousand, three hundred ninety-nine".