40311781 has 2 divisors, whose sum is σ = 40311782. Its totient is φ = 40311780.

The previous prime is 40311779. The next prime is 40311793. The reversal of 40311781 is 18711304.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 32103556 + 8208225 = 5666^2 + 2865^2 .

It is a cyclic number.

It is not a de Polignac number, because 40311781 - 2¹ = 40311779 is a prime.

It is a super-2 number, since 2×40311781² = 3250079374783922, which contains 22 as substring.

Together with 40311779, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40311721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20155890 + 20155891.

It is an arithmetic number, because the mean of its divisors is an integer number (20155891).

Almost surely, 2^40311781 is an apocalyptic number.

It is an amenable number.

40311781 is a deficient number, since it is larger than the sum of its proper divisors (1).

40311781 is an equidigital number, since it uses as much as digits as its factorization.

40311781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 672, while the sum is 25.

The square root of 40311781 is about 6349.1559281530. The cubic root of 40311781 is about 342.8814539888.

The spelling of 40311781 in words is "forty million, three hundred eleven thousand, seven hundred eighty-one".