21347320 has 32 divisors (see below), whose sum is σ = 48172320. Its totient is φ = 8513920.

The previous prime is 21347309. The next prime is 21347329. The reversal of 21347320 is 2374312.

It is a junction number, because it is equal to n+sod(n) for n = 21347291 and 21347300.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21347329) 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, 19590 + ... + 20650.

It is an arithmetic number, because the mean of its divisors is an integer number (1505385).

Almost surely, 2^21347320 is an apocalyptic number.

21347320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21347320 is an abundant number, since it is smaller than the sum of its proper divisors (26825000).

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

21347320 is a wasteful number, since it uses less digits than its factorization.

21347320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1575 (or 1571 counting only the distinct ones).

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

The square root of 21347320 is about 4620.3160065086. The cubic root of 21347320 is about 277.4051078304.

The spelling of 21347320 in words is "twenty-one million, three hundred forty-seven thousand, three hundred twenty".