21747460 has 48 divisors (see below), whose sum is σ = 52569216. Its totient is φ = 7402752.

The previous prime is 21747449. The next prime is 21747493. The reversal of 21747460 is 6474712.

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, 22344 + ... + 23296.

It is an arithmetic number, because the mean of its divisors is an integer number (1095192).

Almost surely, 2^21747460 is an apocalyptic number.

21747460 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 21747460, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26284608).

21747460 is an abundant number, since it is smaller than the sum of its proper divisors (30821756).

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

21747460 is a wasteful number, since it uses less digits than its factorization.

21747460 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1132 (or 1130 counting only the distinct ones).

The product of its (nonzero) digits is 9408, while the sum is 31.

The square root of 21747460 is about 4663.4172020097. The cubic root of 21747460 is about 279.1276420785.

The spelling of 21747460 in words is "twenty-one million, seven hundred forty-seven thousand, four hundred sixty".