21422660 has 48 divisors (see below), whose sum is σ = 53657856. Its totient is φ = 7024512.

The previous prime is 21422641. The next prime is 21422689. The reversal of 21422660 is 6622412.

It is a super-2 number, since 2×21422660² = 917860722951200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (23).

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, 107 + ... + 6546.

It is an arithmetic number, because the mean of its divisors is an integer number (1117872).

Almost surely, 2^21422660 is an apocalyptic number.

21422660 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 21422660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26828928).

21422660 is an abundant number, since it is smaller than the sum of its proper divisors (32235196).

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

21422660 is a wasteful number, since it uses less digits than its factorization.

21422660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6692 (or 6690 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 23.

The square root of 21422660 is about 4628.4619475588. The cubic root of 21422660 is about 277.7310685313.

The spelling of 21422660 in words is "twenty-one million, four hundred twenty-two thousand, six hundred sixty".