31221340021 has 8 divisors (see below), whose sum is σ = 33318190080. Its totient is φ = 29153412288.

The previous prime is 31221340001. The next prime is 31221340043. The reversal of 31221340021 is 12004312213.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 31221340021 - 2²¹ = 31219242869 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31221340001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7228351 + ... + 7232668.

It is an arithmetic number, because the mean of its divisors is an integer number (4164773760).

Almost surely, 2^31221340021 is an apocalyptic number.

It is an amenable number.

31221340021 is a deficient number, since it is larger than the sum of its proper divisors (2096850059).

31221340021 is a wasteful number, since it uses less digits than its factorization.

31221340021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14461163.

The product of its (nonzero) digits is 288, while the sum is 19.

Adding to 31221340021 its reverse (12004312213), we get a palindrome (43225652234).

The spelling of 31221340021 in words is "thirty-one billion, two hundred twenty-one million, three hundred forty thousand, twenty-one".