31020212121 has 8 divisors (see below), whose sum is σ = 41402620704. Its totient is φ = 20658972480.

The previous prime is 31020212089. The next prime is 31020212129. The reversal of 31020212121 is 12121202013.

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

It is not a de Polignac number, because 31020212121 - 2⁵ = 31020212089 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 31020212121.

It is not an unprimeable number, because it can be changed into a prime (31020212129) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5288815 + ... + 5294676.

It is an arithmetic number, because the mean of its divisors is an integer number (5175327588).

Almost surely, 2^31020212121 is an apocalyptic number.

It is an amenable number.

31020212121 is a deficient number, since it is larger than the sum of its proper divisors (10382408583).

31020212121 is a wasteful number, since it uses less digits than its factorization.

31020212121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10584471.

The product of its (nonzero) digits is 48, while the sum is 15.

Adding to 31020212121 its reverse (12121202013), we get a palindrome (43141414134).

The spelling of 31020212121 in words is "thirty-one billion, twenty million, two hundred twelve thousand, one hundred twenty-one".