21437841 has 4 divisors (see below), whose sum is σ = 28583792. Its totient is φ = 14291892.

The previous prime is 21437839. The next prime is 21437851. The reversal of 21437841 is 14873412.

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 not a de Polignac number, because 21437841 - 2¹ = 21437839 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21437799 and 21437808.

It is not an unprimeable number, because it can be changed into a prime (21437851) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3572971 + ... + 3572976.

It is an arithmetic number, because the mean of its divisors is an integer number (7145948).

Almost surely, 2^21437841 is an apocalyptic number.

It is an amenable number.

21437841 is a deficient number, since it is larger than the sum of its proper divisors (7145951).

21437841 is an equidigital number, since it uses as much as digits as its factorization.

21437841 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7145950.

The product of its digits is 5376, while the sum is 30.

The square root of 21437841 is about 4630.1016187553. The cubic root of 21437841 is about 277.7966570220.

The spelling of 21437841 in words is "twenty-one million, four hundred thirty-seven thousand, eight hundred forty-one".