21740180 has 96 divisors (see below), whose sum is σ = 59996160. Its totient is φ = 6410880.

The previous prime is 21740141. The next prime is 21740197. The reversal of 21740180 is 8104712.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 28889 + ... + 29631.

It is an arithmetic number, because the mean of its divisors is an integer number (624960).

Almost surely, 2^21740180 is an apocalyptic number.

21740180 is a gapful number since it is divisible by the number (20) 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 21740180, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29998080).

21740180 is an abundant number, since it is smaller than the sum of its proper divisors (38255980).

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

21740180 is a wasteful number, since it uses less digits than its factorization.

21740180 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 789 (or 787 counting only the distinct ones).

The product of its (nonzero) digits is 448, while the sum is 23.

The square root of 21740180 is about 4662.6365931734. The cubic root of 21740180 is about 279.0964924481.

Adding to 21740180 its reverse (8104712), we get a palindrome (29844892).

The spelling of 21740180 in words is "twenty-one million, seven hundred forty thousand, one hundred eighty".