31491043 has 2 divisors, whose sum is σ = 31491044. Its totient is φ = 31491042.

The previous prime is 31491011. The next prime is 31491077. The reversal of 31491043 is 34019413.

It is a happy number.

It is a weak prime.

It is an emirp because it is prime and its reverse (34019413) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31491043 - 2⁵ = 31491011 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 31490999 and 31491017.

It is not a weakly prime, because it can be changed into another prime (31491143) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15745521 + 15745522.

It is an arithmetic number, because the mean of its divisors is an integer number (15745522).

Almost surely, 2^31491043 is an apocalyptic number.

31491043 is a deficient number, since it is larger than the sum of its proper divisors (1).

31491043 is an equidigital number, since it uses as much as digits as its factorization.

31491043 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1296, while the sum is 25.

The square root of 31491043 is about 5611.6880704473. The cubic root of 31491043 is about 315.7880428478.

The spelling of 31491043 in words is "thirty-one million, four hundred ninety-one thousand, forty-three".