20249851 has 8 divisors (see below), whose sum is σ = 20966400. Its totient is φ = 19537320.

The previous prime is 20249843. The next prime is 20249863. The reversal of 20249851 is 15894202.

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 20249851 - 2³ = 20249843 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20249891) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12210 + ... + 13768.

It is an arithmetic number, because the mean of its divisors is an integer number (2620800).

Almost surely, 2^20249851 is an apocalyptic number.

20249851 is a deficient number, since it is larger than the sum of its proper divisors (716549).

20249851 is a wasteful number, since it uses less digits than its factorization.

20249851 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2009.

The product of its (nonzero) digits is 5760, while the sum is 31.

The square root of 20249851 is about 4499.9834444140. The cubic root of 20249851 is about 272.5674204023.

The spelling of 20249851 in words is "twenty million, two hundred forty-nine thousand, eight hundred fifty-one".