40307781 has 16 divisors (see below), whose sum is σ = 55838720. Its totient is φ = 25835760.

The previous prime is 40307749. The next prime is 40307801. The reversal of 40307781 is 18770304.

It is a happy number.

It is not a de Polignac number, because 40307781 - 2⁵ = 40307749 is a prime.

It is a super-2 number, since 2×40307781² = 3249434418287922, 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 (40307581) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13830 + ... + 16488.

It is an arithmetic number, because the mean of its divisors is an integer number (3489920).

Almost surely, 2^40307781 is an apocalyptic number.

It is an amenable number.

40307781 is a deficient number, since it is larger than the sum of its proper divisors (15530939).

40307781 is a wasteful number, since it uses less digits than its factorization.

40307781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2856.

The product of its (nonzero) digits is 4704, while the sum is 30.

The square root of 40307781 is about 6348.8409178369. The cubic root of 40307781 is about 342.8701126294.

It can be divided in two parts, 4030 and 7781, that added together give a palindrome (11811).

The spelling of 40307781 in words is "forty million, three hundred seven thousand, seven hundred eighty-one".