42639669 has 16 divisors (see below), whose sum is σ = 64515840. Its totient is φ = 27820800.

The previous prime is 42639647. The next prime is 42639679. The reversal of 42639669 is 96693624.

42639669 is a `hidden beast` number, since 4 + 2 + 639 + 6 + 6 + 9 = 666.

It is not a de Polignac number, because 42639669 - 2¹² = 42635573 is a prime.

It is a super-2 number, since 2×42639669² = 3636282744859122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42639679) 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 15 ways as a sum of consecutive naturals, for example, 15532 + ... + 18069.

It is an arithmetic number, because the mean of its divisors is an integer number (4032240).

Almost surely, 2^42639669 is an apocalyptic number.

It is an amenable number.

42639669 is a deficient number, since it is larger than the sum of its proper divisors (21876171).

42639669 is a wasteful number, since it uses less digits than its factorization.

42639669 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33657 (or 33651 counting only the distinct ones).

The product of its digits is 419904, while the sum is 45.

The square root of 42639669 is about 6529.9057420456. The cubic root of 42639669 is about 349.3584683620.

The spelling of 42639669 in words is "forty-two million, six hundred thirty-nine thousand, six hundred sixty-nine".