31540823 has 2 divisors, whose sum is σ = 31540824. Its totient is φ = 31540822.

The previous prime is 31540813. The next prime is 31540837. The reversal of 31540823 is 32804513.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 31540823 - 2¹⁶ = 31475287 is a prime.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 31540792 and 31540801.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31540813) 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, 15770411 + 15770412.

It is an arithmetic number, because the mean of its divisors is an integer number (15770412).

Almost surely, 2^31540823 is an apocalyptic number.

31540823 is a deficient number, since it is larger than the sum of its proper divisors (1).

31540823 is an equidigital number, since it uses as much as digits as its factorization.

31540823 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2880, while the sum is 26.

The square root of 31540823 is about 5616.1217045217. The cubic root of 31540823 is about 315.9543510142.

The spelling of 31540823 in words is "thirty-one million, five hundred forty thousand, eight hundred twenty-three".