31421447 has 2 divisors, whose sum is σ = 31421448. Its totient is φ = 31421446.

The previous prime is 31421441. The next prime is 31421461. The reversal of 31421447 is 74412413.

It is a weak prime.

It is an emirp because it is prime and its reverse (74412413) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31421447 - 2⁴ = 31421431 is a prime.

It is a Chen prime.

It is equal to p_1940336 and since 31421447 and 1940336 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31421441) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15710723 + 15710724.

It is an arithmetic number, because the mean of its divisors is an integer number (15710724).

Almost surely, 2^31421447 is an apocalyptic number.

31421447 is a deficient number, since it is larger than the sum of its proper divisors (1).

31421447 is an equidigital number, since it uses as much as digits as its factorization.

31421447 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2688, while the sum is 26.

The square root of 31421447 is about 5605.4836544227. The cubic root of 31421447 is about 315.5552380798. Note that the first 3 decimals are identical.

The spelling of 31421447 in words is "thirty-one million, four hundred twenty-one thousand, four hundred forty-seven".