209979213 has 32 divisors (see below), whose sum is σ = 305233920. Its totient is φ = 128008320.

The previous prime is 209979197. The next prime is 209979229. The reversal of 209979213 is 312979902.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (209979197) and next prime (209979229).

It is not a de Polignac number, because 209979213 - 2⁴ = 209979197 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (209979713) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 189820 + ... + 190922.

It is an arithmetic number, because the mean of its divisors is an integer number (9538560).

Almost surely, 2^209979213 is an apocalyptic number.

209979213 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

209979213 is a deficient number, since it is larger than the sum of its proper divisors (95254707).

209979213 is a wasteful number, since it uses less digits than its factorization.

209979213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1249.

The product of its (nonzero) digits is 61236, while the sum is 42.

The square root of 209979213 is about 14490.6595088008. The cubic root of 209979213 is about 594.3725825172.

The spelling of 209979213 in words is "two hundred nine million, nine hundred seventy-nine thousand, two hundred thirteen".