42457621 has 4 divisors (see below), whose sum is σ = 42527052. Its totient is φ = 42388192.

The previous prime is 42457607. The next prime is 42457627. The reversal of 42457621 is 12675424.

42457621 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It can be written as a sum of positive squares in 2 ways, for example, as 22752900 + 19704721 = 4770^2 + 4439^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-42457621 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 (42457627) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 33790 + ... + 35023.

It is an arithmetic number, because the mean of its divisors is an integer number (10631763).

Almost surely, 2^42457621 is an apocalyptic number.

It is an amenable number.

42457621 is a deficient number, since it is larger than the sum of its proper divisors (69431).

42457621 is an equidigital number, since it uses as much as digits as its factorization.

42457621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69430.

The product of its digits is 13440, while the sum is 31.

The square root of 42457621 is about 6515.9512736054. The cubic root of 42457621 is about 348.8605694209.

The spelling of 42457621 in words is "forty-two million, four hundred fifty-seven thousand, six hundred twenty-one".