31505032421 has 4 divisors (see below), whose sum is σ = 31948765344. Its totient is φ = 31061299500.

The previous prime is 31505032411. The next prime is 31505032487. The reversal of 31505032421 is 12423050513.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12423050513 = 23 ⋅540132631.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31505032421 is a prime.

It is a super-2 number, since 2×31505032421² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31505032411) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 221866355 + ... + 221866496.

It is an arithmetic number, because the mean of its divisors is an integer number (7987191336).

Almost surely, 2^31505032421 is an apocalyptic number.

It is an amenable number.

31505032421 is a deficient number, since it is larger than the sum of its proper divisors (443732923).

31505032421 is an equidigital number, since it uses as much as digits as its factorization.

31505032421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 443732922.

The product of its (nonzero) digits is 3600, while the sum is 26.

Adding to 31505032421 its reverse (12423050513), we get a palindrome (43928082934).

The spelling of 31505032421 in words is "thirty-one billion, five hundred five million, thirty-two thousand, four hundred twenty-one".