210221091 has 6 divisors (see below), whose sum is σ = 303652700. Its totient is φ = 140147388.

The previous prime is 210221069. The next prime is 210221101. The reversal of 210221091 is 190122012.

It is not a de Polignac number, because 210221091 - 2⁵ = 210221059 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (210221191) 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 5 ways as a sum of consecutive naturals, for example, 11678941 + ... + 11678958.

Almost surely, 2^210221091 is an apocalyptic number.

210221091 is a deficient number, since it is larger than the sum of its proper divisors (93431609).

210221091 is a wasteful number, since it uses less digits than its factorization.

210221091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23357905 (or 23357902 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 18.

The square root of 210221091 is about 14499.0031036620. The cubic root of 210221091 is about 594.6007169800.

The spelling of 210221091 in words is "two hundred ten million, two hundred twenty-one thousand, ninety-one".