21273340 has 24 divisors (see below), whose sum is σ = 48735792. Its totient is φ = 7735680.

The previous prime is 21273319. The next prime is 21273349. The reversal of 21273340 is 4337212.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21273349) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 48129 + ... + 48568.

It is an arithmetic number, because the mean of its divisors is an integer number (2030658).

Almost surely, 2^21273340 is an apocalyptic number.

21273340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21273340 is an abundant number, since it is smaller than the sum of its proper divisors (27462452).

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

21273340 is a wasteful number, since it uses less digits than its factorization.

21273340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 96717 (or 96715 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 22.

The square root of 21273340 is about 4612.3031123290. The cubic root of 21273340 is about 277.0842840653.

The spelling of 21273340 in words is "twenty-one million, two hundred seventy-three thousand, three hundred forty".