21109974 has 8 divisors (see below), whose sum is σ = 42219960. Its totient is φ = 7036656.

The previous prime is 21109973. The next prime is 21109987. The reversal of 21109974 is 47990112.

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

21109974 is an admirable number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21109973) by changing a digit.

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, 1759159 + ... + 1759170.

It is an arithmetic number, because the mean of its divisors is an integer number (5277495).

Almost surely, 2^21109974 is an apocalyptic number.

21109974 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21109974 is a wasteful number, since it uses less digits than its factorization.

21109974 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3518334.

The product of its (nonzero) digits is 4536, while the sum is 33.

The square root of 21109974 is about 4594.5591736314. The cubic root of 21109974 is about 276.3731824393.

The spelling of 21109974 in words is "twenty-one million, one hundred nine thousand, nine hundred seventy-four".