20190851 has 4 divisors (see below), whose sum is σ = 20467512. Its totient is φ = 19914192.

The previous prime is 20190847. The next prime is 20190857. The reversal of 20190851 is 15809102.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20190851 - 2² = 20190847 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 20190851.

It is not an unprimeable number, because it can be changed into a prime (20190857) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 138221 + ... + 138366.

It is an arithmetic number, because the mean of its divisors is an integer number (5116878).

Almost surely, 2^20190851 is an apocalyptic number.

20190851 is a deficient number, since it is larger than the sum of its proper divisors (276661).

20190851 is an equidigital number, since it uses as much as digits as its factorization.

20190851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 276660.

The product of its (nonzero) digits is 720, while the sum is 26.

The square root of 20190851 is about 4493.4230826843. The cubic root of 20190851 is about 272.3024452596.

Adding to 20190851 its reverse (15809102), we get a palindrome (35999953).

The spelling of 20190851 in words is "twenty million, one hundred ninety thousand, eight hundred fifty-one".