21470680 has 64 divisors (see below), whose sum is σ = 60238080. Its totient is φ = 6691200.

The previous prime is 21470653. The next prime is 21470723. The reversal of 21470680 is 8607412.

It is a Harshad number since it is a multiple of its sum of digits (28).

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, 406 + ... + 6565.

It is an arithmetic number, because the mean of its divisors is an integer number (941220).

Almost surely, 2^21470680 is an apocalyptic number.

21470680 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 21470680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30119040).

21470680 is an abundant number, since it is smaller than the sum of its proper divisors (38767400).

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

21470680 is a wasteful number, since it uses less digits than its factorization.

21470680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7000 (or 6996 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 28.

The square root of 21470680 is about 4633.6465121975. The cubic root of 21470680 is about 277.9384298546.

The spelling of 21470680 in words is "twenty-one million, four hundred seventy thousand, six hundred eighty".