20431204645 has 4 divisors (see below), whose sum is σ = 24517445580. Its totient is φ = 16344963712.

The previous prime is 20431204609. The next prime is 20431204649. The reversal of 20431204645 is 54640213402.

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 3652147489 + 16779057156 = 60433^2 + 129534^2 .

It is a cyclic number.

It is not a de Polignac number, because 20431204645 - 2¹³ = 20431196453 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20431204649) 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, 2043120460 + ... + 2043120469.

It is an arithmetic number, because the mean of its divisors is an integer number (6129361395).

Almost surely, 2^20431204645 is an apocalyptic number.

It is an amenable number.

20431204645 is a deficient number, since it is larger than the sum of its proper divisors (4086240935).

20431204645 is an equidigital number, since it uses as much as digits as its factorization.

20431204645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4086240934.

The product of its (nonzero) digits is 23040, while the sum is 31.

The spelling of 20431204645 in words is "twenty billion, four hundred thirty-one million, two hundred four thousand, six hundred forty-five".