21380841 has 28 divisors (see below), whose sum is σ = 32440240. Its totient is φ = 14084280.

The previous prime is 21380813. The next prime is 21380851. The reversal of 21380841 is 14808312.

It is not a de Polignac number, because 21380841 - 2⁵ = 21380809 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21380851) by changing a digit.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 101226 + ... + 101436.

It is an arithmetic number, because the mean of its divisors is an integer number (1158580).

Almost surely, 2^21380841 is an apocalyptic number.

It is an amenable number.

21380841 is a deficient number, since it is larger than the sum of its proper divisors (11059399).

21380841 is an equidigital number, since it uses as much as digits as its factorization.

21380841 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 368 (or 353 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 27.

The square root of 21380841 is about 4623.9421492921. The cubic root of 21380841 is about 277.5502319585.

The spelling of 21380841 in words is "twenty-one million, three hundred eighty thousand, eight hundred forty-one".