21941909 has 8 divisors (see below), whose sum is σ = 23983680. Its totient is φ = 19908000.

The previous prime is 21941879. The next prime is 21941921. The reversal of 21941909 is 90914912.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21941909 - 2¹⁶ = 21876373 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 (21941989) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4952 + ... + 8270.

It is an arithmetic number, because the mean of its divisors is an integer number (2997960).

Almost surely, 2^21941909 is an apocalyptic number.

It is an amenable number.

21941909 is a deficient number, since it is larger than the sum of its proper divisors (2041771).

21941909 is a wasteful number, since it uses less digits than its factorization.

21941909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3931.

The product of its (nonzero) digits is 5832, while the sum is 35.

The square root of 21941909 is about 4684.2191451724. The cubic root of 21941909 is about 279.9570895127.

The spelling of 21941909 in words is "twenty-one million, nine hundred forty-one thousand, nine hundred nine".