20187231 has 16 divisors (see below), whose sum is σ = 28013568. Its totient is φ = 12916800.

The previous prime is 20187229. The next prime is 20187259. The reversal of 20187231 is 13278102.

It is not a de Polignac number, because 20187231 - 2¹ = 20187229 is a prime.

It is a super-2 number, since 2×20187231² = 815048590894722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20187281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11355 + ... + 13011.

It is an arithmetic number, because the mean of its divisors is an integer number (1750848).

Almost surely, 2^20187231 is an apocalyptic number.

20187231 is a deficient number, since it is larger than the sum of its proper divisors (7826337).

20187231 is a wasteful number, since it uses less digits than its factorization.

20187231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1822.

The product of its (nonzero) digits is 672, while the sum is 24.

The square root of 20187231 is about 4493.0202536824. The cubic root of 20187231 is about 272.2861706646.

The spelling of 20187231 in words is "twenty million, one hundred eighty-seven thousand, two hundred thirty-one".