40642661 has 4 divisors (see below), whose sum is σ = 40657152. Its totient is φ = 40628172.

The previous prime is 40642649. The next prime is 40642663. The reversal of 40642661 is 16624604.

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 40642661 - 2¹⁸ = 40380517 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40642663) 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 in 3 ways as a sum of consecutive naturals, for example, 1541 + ... + 9146.

It is an arithmetic number, because the mean of its divisors is an integer number (10164288).

Almost surely, 2^40642661 is an apocalyptic number.

It is an amenable number.

40642661 is a deficient number, since it is larger than the sum of its proper divisors (14491).

40642661 is a wasteful number, since it uses less digits than its factorization.

40642661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14490.

The product of its (nonzero) digits is 6912, while the sum is 29.

The square root of 40642661 is about 6375.1596842746. The cubic root of 40642661 is about 343.8170251233.

The spelling of 40642661 in words is "forty million, six hundred forty-two thousand, six hundred sixty-one".