42904391 has 4 divisors (see below), whose sum is σ = 42990192. Its totient is φ = 42818592.

The previous prime is 42904357. The next prime is 42904429. The reversal of 42904391 is 19340924.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 42904391 - 2¹⁴ = 42888007 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 (42907391) 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, 42146 + ... + 43151.

It is an arithmetic number, because the mean of its divisors is an integer number (10747548).

Almost surely, 2^42904391 is an apocalyptic number.

42904391 is a deficient number, since it is larger than the sum of its proper divisors (85801).

42904391 is an equidigital number, since it uses as much as digits as its factorization.

42904391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85800.

The product of its (nonzero) digits is 7776, while the sum is 32.

The square root of 42904391 is about 6550.1443495544. The cubic root of 42904391 is about 350.0799572426.

The spelling of 42904391 in words is "forty-two million, nine hundred four thousand, three hundred ninety-one".