21941865 has 48 divisors (see below), whose sum is σ = 43692480. Its totient is φ = 10074240.

The previous prime is 21941863. The next prime is 21941867. The reversal of 21941865 is 56814912.

It is an interprime number because it is at equal distance from previous prime (21941863) and next prime (21941867).

It is not a de Polignac number, because 21941865 - 2¹ = 21941863 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21941863) 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, 8239 + ... + 10571.

It is an arithmetic number, because the mean of its divisors is an integer number (910260).

Almost surely, 2^21941865 is an apocalyptic number.

It is an amenable number.

21941865 is a deficient number, since it is larger than the sum of its proper divisors (21750615).

21941865 is a wasteful number, since it uses less digits than its factorization.

21941865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2374 (or 2371 counting only the distinct ones).

The product of its digits is 17280, while the sum is 36.

The square root of 21941865 is about 4684.2144485495. The cubic root of 21941865 is about 279.9569023804.

The spelling of 21941865 in words is "twenty-one million, nine hundred forty-one thousand, eight hundred sixty-five".