40021664 has 12 divisors (see below), whose sum is σ = 78792714. Its totient is φ = 20010816.

The previous prime is 40021661. The next prime is 40021703. The reversal of 40021664 is 46612004.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 30162064 + 9859600 = 5492^2 + 3140^2 .

It is not an unprimeable number, because it can be changed into a prime (40021661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 625307 + ... + 625370.

Almost surely, 2^40021664 is an apocalyptic number.

It is an amenable number.

40021664 is a deficient number, since it is larger than the sum of its proper divisors (38771050).

40021664 is a wasteful number, since it uses less digits than its factorization.

40021664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1250687 (or 1250679 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 23.

The square root of 40021664 is about 6326.2677780821. The cubic root of 40021664 is about 342.0569197238.

Adding to 40021664 its reverse (46612004), we get a palindrome (86633668).

The spelling of 40021664 in words is "forty million, twenty-one thousand, six hundred sixty-four".