21025880 has 32 divisors (see below), whose sum is σ = 47442240. Its totient is φ = 8386560.

The previous prime is 21025867. The next prime is 21025883. The reversal of 21025880 is 8852012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21025883) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22625 + ... + 23535.

It is an arithmetic number, because the mean of its divisors is an integer number (1482570).

Almost surely, 2^21025880 is an apocalyptic number.

21025880 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21025880 is an abundant number, since it is smaller than the sum of its proper divisors (26416360).

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

21025880 is a wasteful number, since it uses less digits than its factorization.

21025880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1499 (or 1495 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 26.

The square root of 21025880 is about 4585.3985650105. The cubic root of 21025880 is about 276.0057059662.

Adding to 21025880 its reverse (8852012), we get a palindrome (29877892).

The spelling of 21025880 in words is "twenty-one million, twenty-five thousand, eight hundred eighty".