21412287 has 48 divisors (see below), whose sum is σ = 35555520. Its totient is φ = 12317184.

The previous prime is 21412277. The next prime is 21412301. The reversal of 21412287 is 78221412.

It is not a de Polignac number, because 21412287 - 2¹⁰ = 21411263 is a prime.

Its product of digits (1792) is a multiple of the sum of its prime factors (224).

It is a self number, because there is not a number n which added to its sum of digits gives 21412287.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21412217) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 196389 + ... + 196497.

It is an arithmetic number, because the mean of its divisors is an integer number (740740).

Almost surely, 2^21412287 is an apocalyptic number.

21412287 is a deficient number, since it is larger than the sum of its proper divisors (14143233).

21412287 is a wasteful number, since it uses less digits than its factorization.

21412287 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 224 (or 221 counting only the distinct ones).

The product of its digits is 1792, while the sum is 27.

The square root of 21412287 is about 4627.3412452509. The cubic root of 21412287 is about 277.6862348601.

Adding to 21412287 its reverse (78221412), we get a palindrome (99633699).

The spelling of 21412287 in words is "twenty-one million, four hundred twelve thousand, two hundred eighty-seven".