21937805 has 8 divisors (see below), whose sum is σ = 26355552. Its totient is φ = 17530128.

The previous prime is 21937771. The next prime is 21937807. The reversal of 21937805 is 50873912.

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 21937805 - 2⁸ = 21937549 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 (21937807) 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, 3662 + ... + 7568.

It is an arithmetic number, because the mean of its divisors is an integer number (3294444).

Almost surely, 2^21937805 is an apocalyptic number.

It is an amenable number.

21937805 is a deficient number, since it is larger than the sum of its proper divisors (4417747).

21937805 is a wasteful number, since it uses less digits than its factorization.

21937805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5035.

The product of its (nonzero) digits is 15120, while the sum is 35.

The square root of 21937805 is about 4683.7810580769. The cubic root of 21937805 is about 279.9396340953.

The spelling of 21937805 in words is "twenty-one million, nine hundred thirty-seven thousand, eight hundred five".