31042421 has 2 divisors, whose sum is σ = 31042422. Its totient is φ = 31042420.

The previous prime is 31042397. The next prime is 31042457. The reversal of 31042421 is 12424013.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 23280625 + 7761796 = 4825^2 + 2786^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31042421 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 31042421.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31042021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15521210 + 15521211.

It is an arithmetic number, because the mean of its divisors is an integer number (15521211).

Almost surely, 2^31042421 is an apocalyptic number.

It is an amenable number.

31042421 is a deficient number, since it is larger than the sum of its proper divisors (1).

31042421 is an equidigital number, since it uses as much as digits as its factorization.

31042421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 31042421 is about 5571.5725787250. The cubic root of 31042421 is about 314.2812907976.

Adding to 31042421 its reverse (12424013), we get a palindrome (43466434).

The spelling of 31042421 in words is "thirty-one million, forty-two thousand, four hundred twenty-one".