21596851 has 16 divisors (see below), whose sum is σ = 24027840. Its totient is φ = 19317760.

The previous prime is 21596837. The next prime is 21596857. The reversal of 21596851 is 15869512.

It is a cyclic number.

It is not a de Polignac number, because 21596851 - 2⁵ = 21596819 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21596851.

It is not an unprimeable number, because it can be changed into a prime (21596857) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 34695 + ... + 35311.

It is an arithmetic number, because the mean of its divisors is an integer number (1501740).

Almost surely, 2^21596851 is an apocalyptic number.

21596851 is a deficient number, since it is larger than the sum of its proper divisors (2430989).

21596851 is a wasteful number, since it uses less digits than its factorization.

21596851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 734.

The product of its digits is 21600, while the sum is 37.

The square root of 21596851 is about 4647.2412246407. The cubic root of 21596851 is about 278.4817956894.

The spelling of 21596851 in words is "twenty-one million, five hundred ninety-six thousand, eight hundred fifty-one".