31021030021 has 4 divisors (see below), whose sum is σ = 31038788512. Its totient is φ = 31003271532.

The previous prime is 31021030013. The next prime is 31021030031. The reversal of 31021030021 is 12003012013.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12003012013 = 307 ⋅39097759.

It is a cyclic number.

It is not a de Polignac number, because 31021030021 - 2³ = 31021030013 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31021029983 and 31021030010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31021030031) 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, 8876625 + ... + 8880118.

It is an arithmetic number, because the mean of its divisors is an integer number (7759697128).

Almost surely, 2^31021030021 is an apocalyptic number.

It is an amenable number.

31021030021 is a deficient number, since it is larger than the sum of its proper divisors (17758491).

31021030021 is a wasteful number, since it uses less digits than its factorization.

31021030021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17758490.

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

Adding to 31021030021 its reverse (12003012013), we get a palindrome (43024042034).

The spelling of 31021030021 in words is "thirty-one billion, twenty-one million, thirty thousand, twenty-one".