20111013 has 12 divisors (see below), whose sum is σ = 31283980. Its totient is φ = 12375936.

The previous prime is 20111011. The next prime is 20111023. The reversal of 20111013 is 31011102.

It can be written as a sum of positive squares in 2 ways, for example, as 7387524 + 12723489 = 2718^2 + 3567^2 .

It is not a de Polignac number, because 20111013 - 2¹ = 20111011 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 20110986 and 20111004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20111011) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 85828 + ... + 86061.

Almost surely, 2^20111013 is an apocalyptic number.

It is an amenable number.

20111013 is a deficient number, since it is larger than the sum of its proper divisors (11172967).

20111013 is a wasteful number, since it uses less digits than its factorization.

20111013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 171908 (or 171905 counting only the distinct ones).

The product of its (nonzero) digits is 6, while the sum is 9.

The square root of 20111013 is about 4484.5304101990. The cubic root of 20111013 is about 271.9430613588.

Adding to 20111013 its reverse (31011102), we get a palindrome (51122115).

The spelling of 20111013 in words is "twenty million, one hundred eleven thousand, thirteen".