20531443439 has 24 divisors (see below), whose sum is σ = 23641854912. Its totient is φ = 17760138240.

The previous prime is 20531443423. The next prime is 20531443459. The reversal of 20531443439 is 93434413502.

It is not a de Polignac number, because 20531443439 - 2⁴ = 20531443423 is a prime.

It is a super-2 number, since 2×20531443439² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20531443459) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 654074 + ... + 684744.

It is an arithmetic number, because the mean of its divisors is an integer number (985077288).

Almost surely, 2^20531443439 is an apocalyptic number.

20531443439 is a deficient number, since it is larger than the sum of its proper divisors (3110411473).

20531443439 is a wasteful number, since it uses less digits than its factorization.

20531443439 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30947 (or 30934 counting only the distinct ones).

The product of its (nonzero) digits is 155520, while the sum is 38.

The spelling of 20531443439 in words is "twenty billion, five hundred thirty-one million, four hundred forty-three thousand, four hundred thirty-nine".