20010631 has 4 divisors (see below), whose sum is σ = 20156832. Its totient is φ = 19864432.

The previous prime is 20010539. The next prime is 20010637. The reversal of 20010631 is 13601002.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20010631 is a prime.

It is a super-2 number, since 2×20010631² = 800850706036322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20010637) 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, 72895 + ... + 73168.

It is an arithmetic number, because the mean of its divisors is an integer number (5039208).

Almost surely, 2^20010631 is an apocalyptic number.

20010631 is a deficient number, since it is larger than the sum of its proper divisors (146201).

20010631 is a wasteful number, since it uses less digits than its factorization.

20010631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 146200.

The product of its (nonzero) digits is 36, while the sum is 13.

The square root of 20010631 is about 4473.3243790273. The cubic root of 20010631 is about 271.4898480965.

Adding to 20010631 its reverse (13601002), we get a palindrome (33611633).

The spelling of 20010631 in words is "twenty million, ten thousand, six hundred thirty-one".