31402121 has 2 divisors, whose sum is σ = 31402122. Its totient is φ = 31402120.

The previous prime is 31402103. The next prime is 31402123. The reversal of 31402121 is 12120413.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16687225 + 14714896 = 4085^2 + 3836^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31402121 is a prime.

Together with 31402123, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 31402096 and 31402105.

It is not a weakly prime, because it can be changed into another prime (31402123) 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 as a sum of consecutive naturals, namely, 15701060 + 15701061.

It is an arithmetic number, because the mean of its divisors is an integer number (15701061).

Almost surely, 2^31402121 is an apocalyptic number.

It is an amenable number.

31402121 is a deficient number, since it is larger than the sum of its proper divisors (1).

31402121 is an equidigital number, since it uses as much as digits as its factorization.

31402121 is an odious number, because the sum of its binary digits is odd.

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

The square root of 31402121 is about 5603.7595415935. The cubic root of 31402121 is about 315.4905299284.

Adding to 31402121 its reverse (12120413), we get a palindrome (43522534).

The spelling of 31402121 in words is "thirty-one million, four hundred two thousand, one hundred twenty-one".