20145243253 has 4 divisors (see below), whose sum is σ = 21330257580. Its totient is φ = 18960228928.

The previous prime is 20145243203. The next prime is 20145243281. The reversal of 20145243253 is 35234254102.

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 16059732529 + 4085510724 = 126727^2 + 63918^2 .

It is a de Polignac number, because none of the positive numbers 2^k-20145243253 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 (20145243203) 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, 592507138 + ... + 592507171.

It is an arithmetic number, because the mean of its divisors is an integer number (5332564395).

Almost surely, 2^20145243253 is an apocalyptic number.

It is an amenable number.

20145243253 is a deficient number, since it is larger than the sum of its proper divisors (1185014327).

20145243253 is a wasteful number, since it uses less digits than its factorization.

20145243253 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1185014326.

The product of its (nonzero) digits is 28800, while the sum is 31.

Adding to 20145243253 its reverse (35234254102), we get a palindrome (55379497355).

The spelling of 20145243253 in words is "twenty billion, one hundred forty-five million, two hundred forty-three thousand, two hundred fifty-three".