221256394 has 16 divisors (see below), whose sum is σ = 357171336. Its totient is φ = 102412800.

The previous prime is 221256383. The next prime is 221256433. The reversal of 221256394 is 493652122.

It can be written as a sum of positive squares in 4 ways, for example, as 90497169 + 130759225 = 9513^2 + 11435^2 .

It is a Harshad number since it is a multiple of its sum of digits (34).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 51267 + ... + 55414.

Almost surely, 2^221256394 is an apocalyptic number.

221256394 is a deficient number, since it is larger than the sum of its proper divisors (135914942).

221256394 is a wasteful number, since it uses less digits than its factorization.

221256394 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106761.

The product of its digits is 25920, while the sum is 34.

The square root of 221256394 is about 14874.6897110494. The cubic root of 221256394 is about 604.8280767325.

The spelling of 221256394 in words is "two hundred twenty-one million, two hundred fifty-six thousand, three hundred ninety-four".