42616781 has 4 divisors (see below), whose sum is σ = 42650364. Its totient is φ = 42583200.

The previous prime is 42616771. The next prime is 42616801. The reversal of 42616781 is 18761624.

42616781 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 21996100 + 20620681 = 4690^2 + 4541^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-42616781 is a prime.

It is a super-2 number, since 2×42616781² = 3632380045603922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42616751) 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, 14810 + ... + 17451.

It is an arithmetic number, because the mean of its divisors is an integer number (10662591).

Almost surely, 2^42616781 is an apocalyptic number.

It is an amenable number.

42616781 is a deficient number, since it is larger than the sum of its proper divisors (33583).

42616781 is a wasteful number, since it uses less digits than its factorization.

42616781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33582.

The product of its digits is 16128, while the sum is 35.

The square root of 42616781 is about 6528.1529547032. The cubic root of 42616781 is about 349.2959479599.

The spelling of 42616781 in words is "forty-two million, six hundred sixteen thousand, seven hundred eighty-one".