209379987 has 12 divisors (see below), whose sum is σ = 306581704. Its totient is φ = 137674080.

The previous prime is 209379979. The next prime is 209379991. The reversal of 209379987 is 789973902.

It is not a de Polignac number, because 209379987 - 2³ = 209379979 is a prime.

It is a super-2 number, since 2×209379987² = 87679957912240338, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (209372987) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 158689 + ... + 160002.

Almost surely, 2^209379987 is an apocalyptic number.

209379987 is a deficient number, since it is larger than the sum of its proper divisors (97201717).

209379987 is a wasteful number, since it uses less digits than its factorization.

209379987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 318770 (or 318767 counting only the distinct ones).

The product of its (nonzero) digits is 1714608, while the sum is 54.

The square root of 209379987 is about 14469.9684519352. The cubic root of 209379987 is about 593.8066489699.

The spelling of 209379987 in words is "two hundred nine million, three hundred seventy-nine thousand, nine hundred eighty-seven".