21142080 has 112 divisors (see below), whose sum is σ = 74615040. Its totient is φ = 5635584.

The previous prime is 21142061. The next prime is 21142087. The reversal of 21142080 is 8024112.

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 (21142087) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7417 + ... + 9863.

Almost surely, 2^21142080 is an apocalyptic number.

21142080 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 21142080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37307520).

21142080 is an abundant number, since it is smaller than the sum of its proper divisors (53472960).

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

21142080 is a wasteful number, since it uses less digits than its factorization.

21142080 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2473 (or 2457 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

The square root of 21142080 is about 4598.0517613441. The cubic root of 21142080 is about 276.5132227631.

Adding to 21142080 its reverse (8024112), we get a palindrome (29166192).

The spelling of 21142080 in words is "twenty-one million, one hundred forty-two thousand, eighty".