21696910 has 8 divisors (see below), whose sum is σ = 39054456. Its totient is φ = 8678760.

The previous prime is 21696877. The next prime is 21696923. The reversal of 21696910 is 1969612.

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

It is a super-4 number, since 4×21696910⁴ (a number of 30 digits) contains 4444 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1084836 + ... + 1084855.

It is an arithmetic number, because the mean of its divisors is an integer number (4881807).

Almost surely, 2^21696910 is an apocalyptic number.

21696910 is a deficient number, since it is larger than the sum of its proper divisors (17357546).

21696910 is a wasteful number, since it uses less digits than its factorization.

21696910 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2169698.

The product of its (nonzero) digits is 5832, while the sum is 34.

The square root of 21696910 is about 4657.9942035172. The cubic root of 21696910 is about 278.9112053262.

The spelling of 21696910 in words is "twenty-one million, six hundred ninety-six thousand, nine hundred ten".