21794851 has 16 divisors (see below), whose sum is σ = 24285184. Its totient is φ = 19432224.

The previous prime is 21794837. The next prime is 21794879. The reversal of 21794851 is 15849712.

It is a 5-Lehmer number, since φ(21794851) divides (21794851-1)⁵.

It is a cyclic number.

It is not a de Polignac number, because 21794851 - 2¹¹ = 21792803 is a prime.

It is a super-2 number, since 2×21794851² = 950031060224402, which contains 22 as substring.

It is a deceptive number, since it divides R_21794850.

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 21794851.

It is not an unprimeable number, because it can be changed into a prime (21794351) 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, 70840 + ... + 71146.

It is an arithmetic number, because the mean of its divisors is an integer number (1517824).

Almost surely, 2^21794851 is an apocalyptic number.

21794851 is a deficient number, since it is larger than the sum of its proper divisors (2490333).

21794851 is a wasteful number, since it uses less digits than its factorization.

21794851 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 490.

The product of its digits is 20160, while the sum is 37.

The square root of 21794851 is about 4668.4955820907. The cubic root of 21794851 is about 279.3302487430.

The spelling of 21794851 in words is "twenty-one million, seven hundred ninety-four thousand, eight hundred fifty-one".