21003260 has 24 divisors (see below), whose sum is σ = 44459520. Its totient is φ = 8334144.

The previous prime is 21003259. The next prime is 21003271. The reversal of 21003260 is 6230012.

21003260 = T₂₈₉₆ + T₂₈₉₇ + ... + T₂₉₀₀.

It is a super-2 number, since 2×21003260² = 882273861255200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1595 + ... + 6674.

It is an arithmetic number, because the mean of its divisors is an integer number (1852480).

Almost surely, 2^21003260 is an apocalyptic number.

21003260 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21003260 is an abundant number, since it is smaller than the sum of its proper divisors (23456260).

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

21003260 is a wasteful number, since it uses less digits than its factorization.

21003260 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8405 (or 8403 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 14.

The square root of 21003260 is about 4582.9313763136. The cubic root of 21003260 is about 275.9066932372.

Adding to 21003260 its reverse (6230012), we get a palindrome (27233272).

The spelling of 21003260 in words is "twenty-one million, three thousand, two hundred sixty".