40161491 has 4 divisors (see below), whose sum is σ = 41546400. Its totient is φ = 38776584.

The previous prime is 40161469. The next prime is 40161503. The reversal of 40161491 is 19416104.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 40161491 - 2¹⁸ = 39899347 is a prime.

It is a super-2 number, since 2×40161491² = 3225890718686162, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 40161491.

It is not an unprimeable number, because it can be changed into a prime (40161091) 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, 692411 + ... + 692468.

It is an arithmetic number, because the mean of its divisors is an integer number (10386600).

Almost surely, 2^40161491 is an apocalyptic number.

40161491 is a deficient number, since it is larger than the sum of its proper divisors (1384909).

40161491 is a wasteful number, since it uses less digits than its factorization.

40161491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1384908.

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 40161491 is about 6337.3094448670. The cubic root of 40161491 is about 342.4548142212.

Adding to 40161491 its reverse (19416104), we get a palindrome (59577595).

The spelling of 40161491 in words is "forty million, one hundred sixty-one thousand, four hundred ninety-one".