221912290 has 16 divisors (see below), whose sum is σ = 401754168. Its totient is φ = 88251136.

The previous prime is 221912261. The next prime is 221912309. The reversal of 221912290 is 92219122.

221912290 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 163405089 + 58507201 = 12783^2 + 7649^2 .

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, 62407 + ... + 65866.

Almost surely, 2^221912290 is an apocalyptic number.

221912290 is a deficient number, since it is larger than the sum of its proper divisors (179841878).

221912290 is a wasteful number, since it uses less digits than its factorization.

221912290 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128453.

The product of its (nonzero) digits is 1296, while the sum is 28.

The square root of 221912290 is about 14896.7207800912. The cubic root of 221912290 is about 605.4251411525.

The spelling of 221912290 in words is "two hundred twenty-one million, nine hundred twelve thousand, two hundred ninety".