31012421 has 6 divisors (see below), whose sum is σ = 34088166. Its totient is φ = 28193000.

The previous prime is 31012411. The next prime is 31012439. The reversal of 31012421 is 12421013.

It can be written as a sum of positive squares in only one way, i.e., 24611521 + 6400900 = 4961^2 + 2530^2 .

It is not a de Polignac number, because 31012421 - 2¹⁴ = 30996037 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 31012396 and 31012405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31012411) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 128030 + ... + 128271.

It is an arithmetic number, because the mean of its divisors is an integer number (5681361).

Almost surely, 2^31012421 is an apocalyptic number.

It is an amenable number.

31012421 is a deficient number, since it is larger than the sum of its proper divisors (3075745).

31012421 is a wasteful number, since it uses less digits than its factorization.

31012421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 256323 (or 256312 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 14.

The square root of 31012421 is about 5568.8796898479. The cubic root of 31012421 is about 314.1800156465.

Adding to 31012421 its reverse (12421013), we get a palindrome (43433434).

The spelling of 31012421 in words is "thirty-one million, twelve thousand, four hundred twenty-one".