20421234531 has 48 divisors (see below), whose sum is σ = 31351756800. Its totient is φ = 12787632000.

The previous prime is 20421234517. The next prime is 20421234553. The reversal of 20421234531 is 13543212402.

20421234531 is a `hidden beast` number, since 2 + 0 + 4 + 2 + 123 + 4 + 531 = 666.

It is not a de Polignac number, because 20421234531 - 2⁵ = 20421234499 is a prime.

It is a super-2 number, since 2×20421234531² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20421234495 and 20421234504.

It is not an unprimeable number, because it can be changed into a prime (20421234131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2271876 + ... + 2280846.

It is an arithmetic number, because the mean of its divisors is an integer number (653161600).

Almost surely, 2^20421234531 is an apocalyptic number.

20421234531 is a deficient number, since it is larger than the sum of its proper divisors (10930522269).

20421234531 is a wasteful number, since it uses less digits than its factorization.

20421234531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9248 (or 9245 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 27.

Adding to 20421234531 its reverse (13543212402), we get a palindrome (33964446933).

The spelling of 20421234531 in words is "twenty billion, four hundred twenty-one million, two hundred thirty-four thousand, five hundred thirty-one".