221991234 has 16 divisors (see below), whose sum is σ = 450609888. Its totient is φ = 72892512.

The previous prime is 221991221. The next prime is 221991247. The reversal of 221991234 is 432199122.

221991234 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (221991221) and next prime (221991247).

It is a junction number, because it is equal to n+sod(n) for n = 221991195 and 221991204.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 275707 + ... + 276510.

It is an arithmetic number, because the mean of its divisors is an integer number (28163118).

Almost surely, 2^221991234 is an apocalyptic number.

221991234 is an abundant number, since it is smaller than the sum of its proper divisors (228618654).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

221991234 is a wasteful number, since it uses less digits than its factorization.

221991234 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 552289.

The product of its digits is 7776, while the sum is 33.

The square root of 221991234 is about 14899.3702551484. The cubic root of 221991234 is about 605.4969247926.

The spelling of 221991234 in words is "two hundred twenty-one million, nine hundred ninety-one thousand, two hundred thirty-four".