42639869 has 4 divisors (see below), whose sum is σ = 42975744. Its totient is φ = 42303996.

The previous prime is 42639853. The next prime is 42639871. The reversal of 42639869 is 96893624.

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 42639869 - 2⁴ = 42639853 is a prime.

It is a super-2 number, since 2×42639869² = 3636316856674322, which contains 22 as substring.

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 (42639899) 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, 167747 + ... + 168000.

It is an arithmetic number, because the mean of its divisors is an integer number (10743936).

Almost surely, 2^42639869 is an apocalyptic number.

It is an amenable number.

42639869 is a deficient number, since it is larger than the sum of its proper divisors (335875).

42639869 is a wasteful number, since it uses less digits than its factorization.

42639869 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 335874.

The product of its digits is 559872, while the sum is 47.

The square root of 42639869 is about 6529.9210561844. The cubic root of 42639869 is about 349.3590145794.

The spelling of 42639869 in words is "forty-two million, six hundred thirty-nine thousand, eight hundred sixty-nine".