21233180 has 24 divisors (see below), whose sum is σ = 44705472. Its totient is φ = 8471232.

The previous prime is 21233161. The next prime is 21233183. The reversal of 21233180 is 8133212.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21233183) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8114 + ... + 10406.

It is an arithmetic number, because the mean of its divisors is an integer number (1862728).

Almost surely, 2^21233180 is an apocalyptic number.

21233180 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21233180 is an abundant number, since it is smaller than the sum of its proper divisors (23472292).

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

21233180 is a wasteful number, since it uses less digits than its factorization.

21233180 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2765 (or 2763 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 21233180 is about 4607.9474823396. The cubic root of 21233180 is about 276.9098135069.

Adding to 21233180 its reverse (8133212), we get a palindrome (29366392).

The spelling of 21233180 in words is "twenty-one million, two hundred thirty-three thousand, one hundred eighty".