42942661 has 4 divisors (see below), whose sum is σ = 43080172. Its totient is φ = 42805152.

The previous prime is 42942643. The next prime is 42942671. The reversal of 42942661 is 16624924.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 10850436 + 32092225 = 3294^2 + 5665^2 .

It is a cyclic number.

It is not a de Polignac number, because 42942661 - 2¹⁹ = 42418373 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 (42942671) 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, 68286 + ... + 68911.

It is an arithmetic number, because the mean of its divisors is an integer number (10770043).

Almost surely, 2^42942661 is an apocalyptic number.

It is an amenable number.

42942661 is a deficient number, since it is larger than the sum of its proper divisors (137511).

42942661 is a wasteful number, since it uses less digits than its factorization.

42942661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 137510.

The product of its digits is 20736, while the sum is 34.

The square root of 42942661 is about 6553.0650080707. The cubic root of 42942661 is about 350.1840148007.

The spelling of 42942661 in words is "forty-two million, nine hundred forty-two thousand, six hundred sixty-one".