20031913 has 6 divisors (see below), whose sum is σ = 22018682. Its totient is φ = 18210720.

The previous prime is 20031901. The next prime is 20031923. The reversal of 20031913 is 31913002.

It can be written as a sum of positive squares in only one way, i.e., 13741849 + 6290064 = 3707^2 + 2508^2 .

It is not a de Polignac number, because 20031913 - 2⁵ = 20031881 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20031923) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 82656 + ... + 82897.

Almost surely, 2^20031913 is an apocalyptic number.

It is an amenable number.

20031913 is a deficient number, since it is larger than the sum of its proper divisors (1986769).

20031913 is a wasteful number, since it uses less digits than its factorization.

20031913 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 165575 (or 165564 counting only the distinct ones).

The product of its (nonzero) digits is 162, while the sum is 19.

The square root of 20031913 is about 4475.7025146897. The cubic root of 20031913 is about 271.5860602856.

Adding to 20031913 its reverse (31913002), we get a palindrome (51944915).

It can be divided in two parts, 2003 and 1913, that added together give a triangular number (3916 = T₈₈).

The spelling of 20031913 in words is "twenty million, thirty-one thousand, nine hundred thirteen".