20102356405 has 4 divisors (see below), whose sum is σ = 24122827692. Its totient is φ = 16081885120.

The previous prime is 20102356403. The next prime is 20102356411. The reversal of 20102356405 is 50465320102.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 50465320102 = 2 ⋅25232660051.

It can be written as a sum of positive squares in 2 ways, for example, as 4745694321 + 15356662084 = 68889^2 + 123922^2 .

It is not a de Polignac number, because 20102356405 - 2¹ = 20102356403 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20102356403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2010235636 + ... + 2010235645.

It is an arithmetic number, because the mean of its divisors is an integer number (6030706923).

Almost surely, 2^20102356405 is an apocalyptic number.

It is an amenable number.

20102356405 is a deficient number, since it is larger than the sum of its proper divisors (4020471287).

20102356405 is an equidigital number, since it uses as much as digits as its factorization.

20102356405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4020471286.

The product of its (nonzero) digits is 7200, while the sum is 28.

Adding to 20102356405 its reverse (50465320102), we get a palindrome (70567676507).

The spelling of 20102356405 in words is "twenty billion, one hundred two million, three hundred fifty-six thousand, four hundred five".