31313424021 has 16 divisors (see below), whose sum is σ = 45565305408. Its totient is φ = 18970121600.

The previous prime is 31313424007. The next prime is 31313424029. The reversal of 31313424021 is 12042431313.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 31313424021 - 2¹¹ = 31313421973 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 31313423982 and 31313424000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31313424029) 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, 109800 + ... + 273281.

It is an arithmetic number, because the mean of its divisors is an integer number (2847831588).

Almost surely, 2^31313424021 is an apocalyptic number.

It is an amenable number.

31313424021 is a deficient number, since it is larger than the sum of its proper divisors (14251881387).

31313424021 is a wasteful number, since it uses less digits than its factorization.

31313424021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 385572.

The product of its (nonzero) digits is 1728, while the sum is 24.

Adding to 31313424021 its reverse (12042431313), we get a palindrome (43355855334).

The spelling of 31313424021 in words is "thirty-one billion, three hundred thirteen million, four hundred twenty-four thousand, twenty-one".