42436781 has 4 divisors (see below), whose sum is σ = 42449952. Its totient is φ = 42423612.

The previous prime is 42436769. The next prime is 42436787. The reversal of 42436781 is 18763424.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-42436781 is a prime.

It is a super-2 number, since 2×42436781² = 3601760763283922, 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 (42436787) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1850 + ... + 9396.

It is an arithmetic number, because the mean of its divisors is an integer number (10612488).

Almost surely, 2^42436781 is an apocalyptic number.

It is an amenable number.

42436781 is a deficient number, since it is larger than the sum of its proper divisors (13171).

42436781 is an equidigital number, since it uses as much as digits as its factorization.

42436781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13170.

The product of its digits is 32256, while the sum is 35.

The square root of 42436781 is about 6514.3519247888. The cubic root of 42436781 is about 348.8034815614.

The spelling of 42436781 in words is "forty-two million, four hundred thirty-six thousand, seven hundred eighty-one".