21851474 has 8 divisors (see below), whose sum is σ = 32922288. Its totient is φ = 10877380.

The previous prime is 21851461. The next prime is 21851503. The reversal of 21851474 is 47415812.

It is a happy number.

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

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21851474.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23612 + ... + 24519.

It is an arithmetic number, because the mean of its divisors is an integer number (4115286).

Almost surely, 2^21851474 is an apocalyptic number.

21851474 is a deficient number, since it is larger than the sum of its proper divisors (11070814).

21851474 is a wasteful number, since it uses less digits than its factorization.

21851474 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48360.

The product of its digits is 8960, while the sum is 32.

The square root of 21851474 is about 4674.5560216987. The cubic root of 21851474 is about 279.5719394572.

The spelling of 21851474 in words is "twenty-one million, eight hundred fifty-one thousand, four hundred seventy-four".