20190631 has 2 divisors, whose sum is σ = 20190632. Its totient is φ = 20190630.

The previous prime is 20190613. The next prime is 20190719. The reversal of 20190631 is 13609102.

Together with previous prime (20190613) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20190631 is a prime.

It is a super-2 number, since 2×20190631² = 815323160356322, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20190601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10095315 + 10095316.

It is an arithmetic number, because the mean of its divisors is an integer number (10095316).

Almost surely, 2^20190631 is an apocalyptic number.

20190631 is a deficient number, since it is larger than the sum of its proper divisors (1).

20190631 is an equidigital number, since it uses as much as digits as its factorization.

20190631 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 324, while the sum is 22.

The square root of 20190631 is about 4493.3986023944. The cubic root of 20190631 is about 272.3014562513.

Adding to 20190631 its reverse (13609102), we get a palindrome (33799733).

The spelling of 20190631 in words is "twenty million, one hundred ninety thousand, six hundred thirty-one".