40000661 has 4 divisors (see below), whose sum is σ = 40034592. Its totient is φ = 39966732.

The previous prime is 40000651. The next prime is 40000669. The reversal of 40000661 is 16600004.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 40000661 - 2²² = 35806357 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40000669) 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, 15131 + ... + 17576.

It is an arithmetic number, because the mean of its divisors is an integer number (10008648).

Almost surely, 2^40000661 is an apocalyptic number.

It is an amenable number.

40000661 is a deficient number, since it is larger than the sum of its proper divisors (33931).

40000661 is a wasteful number, since it uses less digits than its factorization.

40000661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33930.

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 40000661 is about 6324.6075767592. The cubic root of 40000661 is about 341.9970731485.

Adding to 40000661 its reverse (16600004), we get a palindrome (56600665).

The spelling of 40000661 in words is "forty million, six hundred sixty-one", and thus it is an aban number.