209915437980 has 48 divisors (see below), whose sum is σ = 622337536800. Its totient is φ = 52684658688.

The previous prime is 209915437951. The next prime is 209915438021. The reversal of 209915437980 is 89734519902.

It is a super-2 number, since 2×209915437980² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 209915437980.

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, 102898705 + ... + 102900744.

It is an arithmetic number, because the mean of its divisors is an integer number (12965365350).

Almost surely, 2^209915437980 is an apocalyptic number.

209915437980 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

209915437980 is an abundant number, since it is smaller than the sum of its proper divisors (412422098820).

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

209915437980 is a wasteful number, since it uses less digits than its factorization.

209915437980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 205799478 (or 205799476 counting only the distinct ones).

The product of its (nonzero) digits is 4898880, while the sum is 57.

The spelling of 209915437980 in words is "two hundred nine billion, nine hundred fifteen million, four hundred thirty-seven thousand, nine hundred eighty".