221938307 has 4 divisors (see below), whose sum is σ = 222066240. Its totient is φ = 221810376.

The previous prime is 221938291. The next prime is 221938319. The reversal of 221938307 is 703839122.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 221938307 - 2⁴ = 221938291 is a prime.

It is a super-2 number, since 2×221938307² = 98513224228052498, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221938337) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 61328 + ... + 64845.

It is an arithmetic number, because the mean of its divisors is an integer number (55516560).

Almost surely, 2^221938307 is an apocalyptic number.

221938307 is a deficient number, since it is larger than the sum of its proper divisors (127933).

221938307 is a wasteful number, since it uses less digits than its factorization.

221938307 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 127932.

The product of its (nonzero) digits is 18144, while the sum is 35.

The square root of 221938307 is about 14897.5940003747. The cubic root of 221938307 is about 605.4488002452.

The spelling of 221938307 in words is "two hundred twenty-one million, nine hundred thirty-eight thousand, three hundred seven".