21052080 has 120 divisors (see below), whose sum is σ = 80819232. Its totient is φ = 4810752.

The previous prime is 21052079. The next prime is 21052081. The reversal of 21052080 is 8025012.

It is an interprime number because it is at equal distance from previous prime (21052079) and next prime (21052081).

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (21052081) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2952 + ... + 7128.

Almost surely, 2^21052080 is an apocalyptic number.

21052080 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 21052080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40409616).

21052080 is an abundant number, since it is smaller than the sum of its proper divisors (59767152).

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

21052080 is a wasteful number, since it uses less digits than its factorization.

21052080 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4203 (or 4194 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 18.

The square root of 21052080 is about 4588.2545700953. The cubic root of 21052080 is about 276.1203004239.

Adding to 21052080 its reverse (8025012), we get a palindrome (29077092).

The spelling of 21052080 in words is "twenty-one million, fifty-two thousand, eighty".