21273180 has 24 divisors (see below), whose sum is σ = 59565072. Its totient is φ = 5672832.

The previous prime is 21273169. The next prime is 21273181. The reversal of 21273180 is 8137212.

It is a self number, because there is not a number n which added to its sum of digits gives 21273180.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21273181) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 177217 + ... + 177336.

It is an arithmetic number, because the mean of its divisors is an integer number (2481878).

Almost surely, 2^21273180 is an apocalyptic number.

21273180 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21273180 is an abundant number, since it is smaller than the sum of its proper divisors (38291892).

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

21273180 is a wasteful number, since it uses less digits than its factorization.

21273180 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 354565 (or 354563 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 24.

The square root of 21273180 is about 4612.2857673826. The cubic root of 21273180 is about 277.0835893993.

The spelling of 21273180 in words is "twenty-one million, two hundred seventy-three thousand, one hundred eighty".