21913005 has 8 divisors (see below), whose sum is σ = 35060832. Its totient is φ = 11686928.

The previous prime is 21912977. The next prime is 21913037. The reversal of 21913005 is 50031912.

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 21913005 - 2⁹ = 21912493 is a prime.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 730419 + ... + 730448.

It is an arithmetic number, because the mean of its divisors is an integer number (4382604).

Almost surely, 2^21913005 is an apocalyptic number.

It is an amenable number.

21913005 is a deficient number, since it is larger than the sum of its proper divisors (13147827).

21913005 is a wasteful number, since it uses less digits than its factorization.

21913005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1460875.

The product of its (nonzero) digits is 270, while the sum is 21.

The square root of 21913005 is about 4681.1328757043. The cubic root of 21913005 is about 279.8341066635.

Adding to 21913005 its reverse (50031912), we get a palindrome (71944917).

The spelling of 21913005 in words is "twenty-one million, nine hundred thirteen thousand, five".