40009491 has 16 divisors (see below), whose sum is σ = 59643520. Its totient is φ = 26506440.

The previous prime is 40009477. The next prime is 40009511. The reversal of 40009491 is 19490004.

It is not a de Polignac number, because 40009491 - 2⁷ = 40009363 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (40009441) 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, 145 + ... + 8946.

It is an arithmetic number, because the mean of its divisors is an integer number (3727720).

Almost surely, 2^40009491 is an apocalyptic number.

40009491 is a deficient number, since it is larger than the sum of its proper divisors (19634029).

40009491 is a wasteful number, since it uses less digits than its factorization.

40009491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9263 (or 9257 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 40009491 is about 6325.3056052653. The cubic root of 40009491 is about 342.0222361658.

Adding to 40009491 its reverse (19490004), we get a palindrome (59499495).

The spelling of 40009491 in words is "forty million, nine thousand, four hundred ninety-one".