21082520 has 16 divisors (see below), whose sum is σ = 47435760. Its totient is φ = 8432992.

The previous prime is 21082517. The next prime is 21082541. The reversal of 21082520 is 2528012.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 21082492 and 21082501.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 263492 + ... + 263571.

It is an arithmetic number, because the mean of its divisors is an integer number (2964735).

Almost surely, 2^21082520 is an apocalyptic number.

21082520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21082520 is an abundant number, since it is smaller than the sum of its proper divisors (26353240).

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

21082520 is a wasteful number, since it uses less digits than its factorization.

21082520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 527074 (or 527070 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 20.

The square root of 21082520 is about 4591.5705374087. The cubic root of 21082520 is about 276.2533205992.

The spelling of 21082520 in words is "twenty-one million, eighty-two thousand, five hundred twenty".