40051665 has 20 divisors (see below), whose sum is σ = 71797044. Its totient is φ = 21360672.

The previous prime is 40051663. The next prime is 40051667. The reversal of 40051665 is 56615004.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (40051663) and next prime (40051667).

It can be written as a sum of positive squares in 2 ways, for example, as 13549761 + 26501904 = 3681^2 + 5148^2 .

It is not a de Polignac number, because 40051665 - 2¹ = 40051663 is a prime.

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

It is not an unprimeable number, because it can be changed into a prime (40051663) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 49042 + ... + 49851.

Almost surely, 2^40051665 is an apocalyptic number.

40051665 is a gapful number since it is divisible by the number (45) formed by its first and last digit.

It is an amenable number.

40051665 is a deficient number, since it is larger than the sum of its proper divisors (31745379).

40051665 is an equidigital number, since it uses as much as digits as its factorization.

40051665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 98910 (or 98901 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 27.

The square root of 40051665 is about 6328.6384791675. The cubic root of 40051665 is about 342.1423691653.

Adding to 40051665 its reverse (56615004), we get a palindrome (96666669).

The spelling of 40051665 in words is "forty million, fifty-one thousand, six hundred sixty-five".