21286741 has 4 divisors (see below), whose sum is σ = 24327712. Its totient is φ = 18245772.

The previous prime is 21286717. The next prime is 21286751. The reversal of 21286741 is 14768212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21286741 - 2⁵ = 21286709 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21286751) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1520475 + ... + 1520488.

It is an arithmetic number, because the mean of its divisors is an integer number (6081928).

Almost surely, 2^21286741 is an apocalyptic number.

It is an amenable number.

21286741 is a deficient number, since it is larger than the sum of its proper divisors (3040971).

21286741 is an equidigital number, since it uses as much as digits as its factorization.

21286741 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3040970.

The product of its digits is 5376, while the sum is 31.

The square root of 21286741 is about 4613.7556285525. The cubic root of 21286741 is about 277.1424543238.

The spelling of 21286741 in words is "twenty-one million, two hundred eighty-six thousand, seven hundred forty-one".