40327981 has 4 divisors (see below), whose sum is σ = 40340700. Its totient is φ = 40315264.

The previous prime is 40327967. The next prime is 40328027. The reversal of 40327981 is 18972304.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 35880100 + 4447881 = 5990^2 + 2109^2 .

It is a cyclic number.

It is not a de Polignac number, because 40327981 - 2⁷ = 40327853 is a prime.

It is a super-2 number, since 2×40327981² = 3252692103072722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40327181) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2685 + ... + 9373.

It is an arithmetic number, because the mean of its divisors is an integer number (10085175).

Almost surely, 2^40327981 is an apocalyptic number.

It is an amenable number.

40327981 is a deficient number, since it is larger than the sum of its proper divisors (12719).

40327981 is an equidigital number, since it uses as much as digits as its factorization.

40327981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12718.

The product of its (nonzero) digits is 12096, while the sum is 34.

The square root of 40327981 is about 6350.4315601383. The cubic root of 40327981 is about 342.9273788235.

The spelling of 40327981 in words is "forty million, three hundred twenty-seven thousand, nine hundred eighty-one".