20310200021 has 4 divisors (see below), whose sum is σ = 20415434412. Its totient is φ = 20204965632.

The previous prime is 20310200017. The next prime is 20310200023. The reversal of 20310200021 is 12000201302.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12000201302 = 2 ⋅6000100651.

It can be written as a sum of positive squares in 2 ways, for example, as 6354321796 + 13955878225 = 79714^2 + 118135^2 .

It is a cyclic number.

It is not a de Polignac number, because 20310200021 - 2² = 20310200017 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20310199975 and 20310200011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20310200023) 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, 52616906 + ... + 52617291.

It is an arithmetic number, because the mean of its divisors is an integer number (5103858603).

Almost surely, 2^20310200021 is an apocalyptic number.

It is an amenable number.

20310200021 is a deficient number, since it is larger than the sum of its proper divisors (105234391).

20310200021 is a wasteful number, since it uses less digits than its factorization.

20310200021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 105234390.

The product of its (nonzero) digits is 24, while the sum is 11.

Adding to 20310200021 its reverse (12000201302), we get a palindrome (32310401323).

The spelling of 20310200021 in words is "twenty billion, three hundred ten million, two hundred thousand, twenty-one".