21260364 has 48 divisors (see below), whose sum is σ = 51744000. Its totient is φ = 6785856.

The previous prime is 21260359. The next prime is 21260377. The reversal of 21260364 is 46306212.

21260364 = T₁₀₇ + T₁₀₈ + ... + T₅₀₄.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 69099 + ... + 69405.

It is an arithmetic number, because the mean of its divisors is an integer number (1078000).

Almost surely, 2^21260364 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21260364, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25872000).

21260364 is an abundant number, since it is smaller than the sum of its proper divisors (30483636).

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

21260364 is a wasteful number, since it uses less digits than its factorization.

21260364 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 542 (or 540 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 24.

The square root of 21260364 is about 4610.8962252473. The cubic root of 21260364 is about 277.0279353373.

Adding to 21260364 its reverse (46306212), we get a palindrome (67566576).

The spelling of 21260364 in words is "twenty-one million, two hundred sixty thousand, three hundred sixty-four".