31123223021 has 16 divisors (see below), whose sum is σ = 34041990528. Its totient is φ = 28219464000.

The previous prime is 31123223003. The next prime is 31123223029. The reversal of 31123223021 is 12032232113.

It is a cyclic number.

It is not a de Polignac number, because 31123223021 - 2¹⁸ = 31122960877 is a prime.

It is a super-3 number, since 3×31123223021³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31123222984 and 31123223002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31123223029) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8194895 + ... + 8198691.

It is an arithmetic number, because the mean of its divisors is an integer number (2127624408).

Almost surely, 2^31123223021 is an apocalyptic number.

It is an amenable number.

31123223021 is a deficient number, since it is larger than the sum of its proper divisors (2918767507).

31123223021 is a wasteful number, since it uses less digits than its factorization.

31123223021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5572.

The product of its (nonzero) digits is 432, while the sum is 20.

Adding to 31123223021 its reverse (12032232113), we get a palindrome (43155455134).

The spelling of 31123223021 in words is "thirty-one billion, one hundred twenty-three million, two hundred twenty-three thousand, twenty-one".