20198851 has 4 divisors (see below), whose sum is σ = 20210632. Its totient is φ = 20187072.

The previous prime is 20198837. The next prime is 20198903. The reversal of 20198851 is 15889102.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 20198851 - 2¹⁷ = 20067779 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20198821) 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, 2766 + ... + 6931.

It is an arithmetic number, because the mean of its divisors is an integer number (5052658).

Almost surely, 2^20198851 is an apocalyptic number.

20198851 is a deficient number, since it is larger than the sum of its proper divisors (11781).

20198851 is an equidigital number, since it uses as much as digits as its factorization.

20198851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11780.

The product of its (nonzero) digits is 5760, while the sum is 34.

The square root of 20198851 is about 4494.3131844588. The cubic root of 20198851 is about 272.3384043171.

The spelling of 20198851 in words is "twenty million, one hundred ninety-eight thousand, eight hundred fifty-one".