21263460 has 24 divisors (see below), whose sum is σ = 59537856. Its totient is φ = 5670240.

The previous prime is 21263453. The next prime is 21263471. The reversal of 21263460 is 6436212.

It is a self number, because there is not a number n which added to its sum of digits gives 21263460.

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, 177136 + ... + 177255.

It is an arithmetic number, because the mean of its divisors is an integer number (2480744).

Almost surely, 2^21263460 is an apocalyptic number.

21263460 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21263460 is an abundant number, since it is smaller than the sum of its proper divisors (38274396).

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

21263460 is a wasteful number, since it uses less digits than its factorization.

21263460 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 354403 (or 354401 counting only the distinct ones).

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

The square root of 21263460 is about 4611.2319395146. The cubic root of 21263460 is about 277.0413819063.

Adding to 21263460 its reverse (6436212), we get a palindrome (27699672).

The spelling of 21263460 in words is "twenty-one million, two hundred sixty-three thousand, four hundred sixty".