40690391 has 16 divisors (see below), whose sum is σ = 47763456. Its totient is φ = 33941376.

The previous prime is 40690387. The next prime is 40690399. The reversal of 40690391 is 19309604.

It is not a de Polignac number, because 40690391 - 2² = 40690387 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40690399) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 110690 + ... + 111056.

It is an arithmetic number, because the mean of its divisors is an integer number (2985216).

Almost surely, 2^40690391 is an apocalyptic number.

40690391 is a deficient number, since it is larger than the sum of its proper divisors (7073065).

40690391 is a wasteful number, since it uses less digits than its factorization.

40690391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 758.

The product of its (nonzero) digits is 5832, while the sum is 32.

The square root of 40690391 is about 6378.9020215081. The cubic root of 40690391 is about 343.9515632857.

Adding to 40690391 its reverse (19309604), we get a palindrome (59999995).

The spelling of 40690391 in words is "forty million, six hundred ninety thousand, three hundred ninety-one".