31020130021 has 4 divisors (see below), whose sum is σ = 31149921600. Its totient is φ = 30890338444.

The previous prime is 31020130019. The next prime is 31020130051. The reversal of 31020130021 is 12003102013.

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 not a de Polignac number, because 31020130021 - 2¹ = 31020130019 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 31020129983 and 31020130010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31020130051) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 64895431 + ... + 64895908.

It is an arithmetic number, because the mean of its divisors is an integer number (7787480400).

Almost surely, 2^31020130021 is an apocalyptic number.

It is an amenable number.

31020130021 is a deficient number, since it is larger than the sum of its proper divisors (129791579).

31020130021 is a wasteful number, since it uses less digits than its factorization.

31020130021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129791578.

The product of its (nonzero) digits is 36, while the sum is 13.

Adding to 31020130021 its reverse (12003102013), we get a palindrome (43023232034).

The spelling of 31020130021 in words is "thirty-one billion, twenty million, one hundred thirty thousand, twenty-one".