209801436 has 48 divisors (see below), whose sum is σ = 529345824. Its totient is φ = 64290816.

The previous prime is 209801419. The next prime is 209801441. The reversal of 209801436 is 634108902.

It is a junction number, because it is equal to n+sod(n) for n = 209801397 and 209801406.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 37476 + ... + 42708.

It is an arithmetic number, because the mean of its divisors is an integer number (11028038).

Almost surely, 2^209801436 is an apocalyptic number.

209801436 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 209801436, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (264672912).

209801436 is an abundant number, since it is smaller than the sum of its proper divisors (319544388).

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

209801436 is a wasteful number, since it uses less digits than its factorization.

209801436 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5510 (or 5508 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 33.

The square root of 209801436 is about 14484.5240170328. The cubic root of 209801436 is about 594.2047951007.

The spelling of 209801436 in words is "two hundred nine million, eight hundred one thousand, four hundred thirty-six".