31224241021 has 4 divisors (see below), whose sum is σ = 31500561852. Its totient is φ = 30947920192.

The previous prime is 31224241007. The next prime is 31224241049. The reversal of 31224241021 is 12014242213.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12014242213 = 37 ⋅324709249.

It can be written as a sum of positive squares in 2 ways, for example, as 383964025 + 30840276996 = 19595^2 + 175614^2 .

It is a cyclic number.

It is not a de Polignac number, because 31224241021 - 2²⁵ = 31190686589 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31224240983 and 31224241001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31224241091) 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, 138160246 + ... + 138160471.

It is an arithmetic number, because the mean of its divisors is an integer number (7875140463).

Almost surely, 2^31224241021 is an apocalyptic number.

It is an amenable number.

31224241021 is a deficient number, since it is larger than the sum of its proper divisors (276320831).

31224241021 is a wasteful number, since it uses less digits than its factorization.

31224241021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 276320830.

The product of its (nonzero) digits is 768, while the sum is 22.

Adding to 31224241021 its reverse (12014242213), we get a palindrome (43238483234).

The spelling of 31224241021 in words is "thirty-one billion, two hundred twenty-four million, two hundred forty-one thousand, twenty-one".