20145440431 has 16 divisors (see below), whose sum is σ = 20894041600. Its totient is φ = 19408546080.

The previous prime is 20145440423. The next prime is 20145440449. The reversal of 20145440431 is 13404454102.

It is a cyclic number.

It is not a de Polignac number, because 20145440431 - 2³ = 20145440423 is a prime.

It is a super-2 number, since 2×20145440431² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20145440431.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20145440461) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1547110 + ... + 1560076.

It is an arithmetic number, because the mean of its divisors is an integer number (1305877600).

Almost surely, 2^20145440431 is an apocalyptic number.

20145440431 is a deficient number, since it is larger than the sum of its proper divisors (748601169).

20145440431 is a wasteful number, since it uses less digits than its factorization.

20145440431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13414.

The product of its (nonzero) digits is 7680, while the sum is 28.

Adding to 20145440431 its reverse (13404454102), we get a palindrome (33549894533).

It can be divided in two parts, 2014 and 5440431, that added together give a palindrome (5442445).

The spelling of 20145440431 in words is "twenty billion, one hundred forty-five million, four hundred forty thousand, four hundred thirty-one".