21273560 has 64 divisors (see below), whose sum is σ = 59685120. Its totient is φ = 6629760.

The previous prime is 21273509. The next prime is 21273583. The reversal of 21273560 is 6537212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 374 + ... + 6533.

It is an arithmetic number, because the mean of its divisors is an integer number (932580).

Almost surely, 2^21273560 is an apocalyptic number.

21273560 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 21273560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29842560).

21273560 is an abundant number, since it is smaller than the sum of its proper divisors (38411560).

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

21273560 is a wasteful number, since it uses less digits than its factorization.

21273560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6936 (or 6932 counting only the distinct ones).

The product of its (nonzero) digits is 2520, while the sum is 26.

The square root of 21273560 is about 4612.3269615239. The cubic root of 21273560 is about 277.0852392253.

The spelling of 21273560 in words is "twenty-one million, two hundred seventy-three thousand, five hundred sixty".