442018391 has 16 divisors (see below), whose sum is σ = 460961280. Its totient is φ = 423499680.

The previous prime is 442018387. The next prime is 442018397. The reversal of 442018391 is 193810244.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 442018391 - 2² = 442018387 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 (442018397) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1231070 + ... + 1231428.

It is an arithmetic number, because the mean of its divisors is an integer number (28810080).

Almost surely, 2^442018391 is an apocalyptic number.

442018391 is a deficient number, since it is larger than the sum of its proper divisors (18942889).

442018391 is a wasteful number, since it uses less digits than its factorization.

442018391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 814.

The product of its (nonzero) digits is 6912, while the sum is 32.

The square root of 442018391 is about 21024.2334224104. The cubic root of 442018391 is about 761.7517251565.

The spelling of 442018391 in words is "four hundred forty-two million, eighteen thousand, three hundred ninety-one".