209475640020 has 48 divisors (see below), whose sum is σ = 593956258560. Its totient is φ = 55153078656.

The previous prime is 209475640001. The next prime is 209475640021. The reversal of 209475640020 is 20046574902.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (209475640021) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22091847 + ... + 22101326.

It is an arithmetic number, because the mean of its divisors is an integer number (12374088720).

Almost surely, 2^209475640020 is an apocalyptic number.

209475640020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

209475640020 is an abundant number, since it is smaller than the sum of its proper divisors (384480618540).

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

209475640020 is a wasteful number, since it uses less digits than its factorization.

209475640020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44193264 (or 44193262 counting only the distinct ones).

The product of its (nonzero) digits is 120960, while the sum is 39.

The spelling of 209475640020 in words is "two hundred nine billion, four hundred seventy-five million, six hundred forty thousand, twenty".