21025080 has 48 divisors (see below), whose sum is σ = 68332680. Its totient is φ = 5606592.

The previous prime is 21025051. The next prime is 21025091. The reversal of 21025080 is 8052012.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 28842 + ... + 29561.

Almost surely, 2^21025080 is an apocalyptic number.

21025080 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21025080 is an abundant number, since it is smaller than the sum of its proper divisors (47307600).

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

21025080 is a wasteful number, since it uses less digits than its factorization.

21025080 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58420 (or 58413 counting only the distinct ones).

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

The square root of 21025080 is about 4585.3113307604. The cubic root of 21025080 is about 276.0022054014.

Adding to 21025080 its reverse (8052012), we get a palindrome (29077092).

The spelling of 21025080 in words is "twenty-one million, twenty-five thousand, eighty".