21371853 has 8 divisors (see below), whose sum is σ = 29734848. Its totient is φ = 13628384.

The previous prime is 21371851. The next prime is 21371881. The reversal of 21371853 is 35817312.

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 21371853 - 2¹ = 21371851 is a prime.

It is a super-2 number, since 2×21371853² = 913512201307218, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21371853.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21371851) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 154800 + ... + 154937.

It is an arithmetic number, because the mean of its divisors is an integer number (3716856).

Almost surely, 2^21371853 is an apocalyptic number.

21371853 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

21371853 is a deficient number, since it is larger than the sum of its proper divisors (8362995).

21371853 is a wasteful number, since it uses less digits than its factorization.

21371853 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 309763.

The product of its digits is 5040, while the sum is 30.

The square root of 21371853 is about 4622.9701491574. The cubic root of 21371853 is about 277.5113346559.

The spelling of 21371853 in words is "twenty-one million, three hundred seventy-one thousand, eight hundred fifty-three".