208287990 has 32 divisors (see below), whose sum is σ = 555435360. Its totient is φ = 55543392.

The previous prime is 208287979. The next prime is 208288007. The reversal of 208287990 is 99782802.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 385449 + ... + 385988.

It is an arithmetic number, because the mean of its divisors is an integer number (17357355).

Almost surely, 2^208287990 is an apocalyptic number.

208287990 is an abundant number, since it is smaller than the sum of its proper divisors (347147370).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

208287990 is a wasteful number, since it uses less digits than its factorization.

208287990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 771453 (or 771447 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 45.

The square root of 208287990 is about 14432.1859051219. The cubic root of 208287990 is about 592.7725392547.

The spelling of 208287990 in words is "two hundred eight million, two hundred eighty-seven thousand, nine hundred ninety".