31030121020 has 48 divisors (see below), whose sum is σ = 66823339968. Its totient is φ = 12096483840.

The previous prime is 31030121009. The next prime is 31030121039. The reversal of 31030121020 is 2012103013.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 773374 + ... + 812506.

It is an arithmetic number, because the mean of its divisors is an integer number (1392152916).

Almost surely, 2^31030121020 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31030121020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33411669984).

31030121020 is an abundant number, since it is smaller than the sum of its proper divisors (35793218948).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

31030121020 is a wasteful number, since it uses less digits than its factorization.

31030121020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40150 (or 40148 counting only the distinct ones).

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

Adding to 31030121020 its reverse (2012103013), we get a palindrome (33042224033).

The spelling of 31030121020 in words is "thirty-one billion, thirty million, one hundred twenty-one thousand, twenty".