209922989 has 4 divisors (see below), whose sum is σ = 209969820. Its totient is φ = 209876160.

The previous prime is 209922959. The next prime is 209923031. The reversal of 209922989 is 989229902.

209922989 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It can be written as a sum of positive squares in 2 ways, for example, as 133010089 + 76912900 = 11533^2 + 8770^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-209922989 is a prime.

It is a super-2 number, since 2×209922989² = 88135322621388242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (209922929) 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, 15884 + ... + 25925.

It is an arithmetic number, because the mean of its divisors is an integer number (52492455).

Almost surely, 2^209922989 is an apocalyptic number.

It is an amenable number.

209922989 is a deficient number, since it is larger than the sum of its proper divisors (46831).

209922989 is an equidigital number, since it uses as much as digits as its factorization.

209922989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46830.

The product of its (nonzero) digits is 419904, while the sum is 50.

The square root of 209922989 is about 14488.7193706000. The cubic root of 209922989 is about 594.3195280795.

The spelling of 209922989 in words is "two hundred nine million, nine hundred twenty-two thousand, nine hundred eighty-nine".