20102121013 has 4 divisors (see below), whose sum is σ = 21648438028. Its totient is φ = 18555804000.

The previous prime is 20102120993. The next prime is 20102121073. The reversal of 20102121013 is 31012120102.

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

It can be written as a sum of positive squares in 2 ways, for example, as 9861085809 + 10241035204 = 99303^2 + 101198^2 .

It is a cyclic number.

It is not a de Polignac number, because 20102121013 - 2⁵ = 20102120981 is a prime.

It is a super-2 number, since 2×20102121013² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (13), and also a Moran number because the ratio is a prime number: 1546317001 = 20102121013 / (2 + 0 + 1 + 0 + 2 + 1 + 2 + 1 + 0 + 1 + 3).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20102120984 and 20102121002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20102121073) 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, 773158488 + ... + 773158513.

It is an arithmetic number, because the mean of its divisors is an integer number (5412109507).

Almost surely, 2^20102121013 is an apocalyptic number.

It is an amenable number.

20102121013 is a deficient number, since it is larger than the sum of its proper divisors (1546317015).

20102121013 is a wasteful number, since it uses less digits than its factorization.

20102121013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1546317014.

The product of its (nonzero) digits is 24, while the sum is 13.

Adding to 20102121013 its reverse (31012120102), we get a palindrome (51114241115).

The spelling of 20102121013 in words is "twenty billion, one hundred two million, one hundred twenty-one thousand, thirteen".