40161665 has 8 divisors (see below), whose sum is σ = 49856040. Its totient is φ = 31021312.

The previous prime is 40161643. The next prime is 40161677. The reversal of 40161665 is 56616104.

It can be written as a sum of positive squares in 4 ways, for example, as 14070001 + 26091664 = 3751^2 + 5108^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 40161665 - 2¹⁸ = 39899521 is a prime.

It is a super-2 number, since 2×40161665² = 3225918671144450, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 138344 + ... + 138633.

It is an arithmetic number, because the mean of its divisors is an integer number (6232005).

Almost surely, 2^40161665 is an apocalyptic number.

It is an amenable number.

40161665 is a deficient number, since it is larger than the sum of its proper divisors (9694375).

40161665 is a wasteful number, since it uses less digits than its factorization.

40161665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 277011.

The product of its (nonzero) digits is 4320, while the sum is 29.

The square root of 40161665 is about 6337.3231730755. The cubic root of 40161665 is about 342.4553087832.

Adding to 40161665 its reverse (56616104), we get a palindrome (96777769).

The spelling of 40161665 in words is "forty million, one hundred sixty-one thousand, six hundred sixty-five".