209870628 has 36 divisors (see below), whose sum is σ = 538266960. Its totient is φ = 63596720.

The previous prime is 209870621. The next prime is 209870629. The reversal of 209870628 is 826078902.

It is a happy number.

It is a super-2 number, since 2×209870628² = 88091360994228768, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 209870628.

It is not an unprimeable number, because it can be changed into a prime (209870621) 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, 70818 + ... + 73721.

It is an arithmetic number, because the mean of its divisors is an integer number (14951860).

Almost surely, 2^209870628 is an apocalyptic number.

It is an amenable number.

209870628 is an abundant number, since it is smaller than the sum of its proper divisors (328396332).

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

209870628 is a wasteful number, since it uses less digits than its factorization.

209870628 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144568 (or 144555 counting only the distinct ones).

The product of its (nonzero) digits is 96768, while the sum is 42.

The square root of 209870628 is about 14486.9123004179. The cubic root of 209870628 is about 594.2701103499.

The spelling of 209870628 in words is "two hundred nine million, eight hundred seventy thousand, six hundred twenty-eight".