42536781 has 12 divisors (see below), whose sum is σ = 70219552. Its totient is φ = 24306696.

The previous prime is 42536777. The next prime is 42536797. The reversal of 42536781 is 18763524.

42536781 is a `hidden beast` number, since 42 + 536 + 7 + 81 = 666.

It is not a de Polignac number, because 42536781 - 2² = 42536777 is a prime.

It is a super-2 number, since 2×42536781² = 3618755475683922, which contains 22 as substring.

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 (42536381) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 337531 + ... + 337656.

Almost surely, 2^42536781 is an apocalyptic number.

It is an amenable number.

42536781 is a deficient number, since it is larger than the sum of its proper divisors (27682771).

42536781 is a wasteful number, since it uses less digits than its factorization.

42536781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 675200 (or 675197 counting only the distinct ones).

The product of its digits is 40320, while the sum is 36.

The square root of 42536781 is about 6522.0227690495. The cubic root of 42536781 is about 349.0772455405.

The spelling of 42536781 in words is "forty-two million, five hundred thirty-six thousand, seven hundred eighty-one".