21039080 has 96 divisors (see below), whose sum is σ = 52669440. Its totient is φ = 7551360.

The previous prime is 21039079. The next prime is 21039091. The reversal of 21039080 is 8093012.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 447617 + ... + 447663.

It is an arithmetic number, because the mean of its divisors is an integer number (548640).

Almost surely, 2^21039080 is an apocalyptic number.

21039080 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 21039080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26334720).

21039080 is an abundant number, since it is smaller than the sum of its proper divisors (31630360).

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

21039080 is a wasteful number, since it uses less digits than its factorization.

21039080 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 127 (or 104 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 23.

The square root of 21039080 is about 4586.8376906099. The cubic root of 21039080 is about 276.0634524699.

The spelling of 21039080 in words is "twenty-one million, thirty-nine thousand, eighty".