31525331243221 has 4 divisors (see below), whose sum is σ = 31525465565344. Its totient is φ = 31525196921100.

The previous prime is 31525331243209. The next prime is 31525331243291. The reversal of 31525331243221 is 12234213352513.

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.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31525331243221 is a prime.

It is a super-2 number, since 2×31525331243221² (a number of 28 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 (31525331243291) 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, 66808395 + ... + 67278616.

It is an arithmetic number, because the mean of its divisors is an integer number (7881366391336).

Almost surely, 2^{31525331243221} is an apocalyptic number.

It is an amenable number.

31525331243221 is a deficient number, since it is larger than the sum of its proper divisors (134322123).

31525331243221 is a wasteful number, since it uses less digits than its factorization.

31525331243221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 134322122.

The product of its digits is 129600, while the sum is 37.

Adding to 31525331243221 its reverse (12234213352513), we get a palindrome (43759544595734).

The spelling of 31525331243221 in words is "thirty-one trillion, five hundred twenty-five billion, three hundred thirty-one million, two hundred forty-three thousand, two hundred twenty-one".