209471040 has 84 divisors (see below), whose sum is σ = 720503004. Its totient is φ = 55858176.

The previous prime is 209471027. The next prime is 209471047. The reversal of 209471040 is 40174902.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 141705216 + 67765824 = 11904^2 + 8232^2 .

It is a junction number, because it is equal to n+sod(n) for n = 209470995 and 209471013.

It is not an unprimeable number, because it can be changed into a prime (209471047) 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 11 ways as a sum of consecutive naturals, for example, 33487 + ... + 39246.

Almost surely, 2^209471040 is an apocalyptic number.

209471040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

209471040 is an abundant number, since it is smaller than the sum of its proper divisors (511031964).

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

209471040 is a wasteful number, since it uses less digits than its factorization.

209471040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72756 (or 72743 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 209471040 is about 14473.1143849553. The cubic root of 209471040 is about 593.8927126572.

The spelling of 209471040 in words is "two hundred nine million, four hundred seventy-one thousand, forty".