42735821 has 4 divisors (see below), whose sum is σ = 44209500. Its totient is φ = 41262144.

The previous prime is 42735811. The next prime is 42735839. The reversal of 42735821 is 12853724.

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 10982596 + 31753225 = 3314^2 + 5635^2 .

It is a cyclic number.

It is not a de Polignac number, because 42735821 - 2⁶ = 42735757 is a prime.

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 (42735811) 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 3 ways as a sum of consecutive naturals, for example, 736796 + ... + 736853.

It is an arithmetic number, because the mean of its divisors is an integer number (11052375).

Almost surely, 2^42735821 is an apocalyptic number.

It is an amenable number.

42735821 is a deficient number, since it is larger than the sum of its proper divisors (1473679).

42735821 is a wasteful number, since it uses less digits than its factorization.

42735821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1473678.

The product of its digits is 13440, while the sum is 32.

The square root of 42735821 is about 6537.2640301582. The cubic root of 42735821 is about 349.6208710989.

The spelling of 42735821 in words is "forty-two million, seven hundred thirty-five thousand, eight hundred twenty-one".