42905921 has 8 divisors (see below), whose sum is σ = 44128800. Its totient is φ = 41699680.

The previous prime is 42905917. The next prime is 42905981. The reversal of 42905921 is 12950924.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 42905921 - 2² = 42905917 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (42905981) 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 7 ways as a sum of consecutive naturals, for example, 1166 + ... + 9336.

It is an arithmetic number, because the mean of its divisors is an integer number (5516100).

Almost surely, 2^42905921 is an apocalyptic number.

It is an amenable number.

42905921 is a deficient number, since it is larger than the sum of its proper divisors (1222879).

42905921 is an equidigital number, since it uses as much as digits as its factorization.

42905921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8319.

The product of its (nonzero) digits is 6480, while the sum is 32.

The square root of 42905921 is about 6550.2611398325. The cubic root of 42905921 is about 350.0841185569.

The spelling of 42905921 in words is "forty-two million, nine hundred five thousand, nine hundred twenty-one".