42877781 has 4 divisors (see below), whose sum is σ = 43102464. Its totient is φ = 42653100.

The previous prime is 42877777. The next prime is 42877801. The reversal of 42877781 is 18777824.

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.

It is a cyclic number.

It is not a de Polignac number, because 42877781 - 2² = 42877777 is a prime.

It is a super-2 number, since 2×42877781² = 3677008206967922, 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 (42877721) 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, 112055 + ... + 112436.

It is an arithmetic number, because the mean of its divisors is an integer number (10775616).

Almost surely, 2^42877781 is an apocalyptic number.

It is an amenable number.

42877781 is a deficient number, since it is larger than the sum of its proper divisors (224683).

42877781 is a wasteful number, since it uses less digits than its factorization.

42877781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 224682.

The product of its digits is 175616, while the sum is 44.

The square root of 42877781 is about 6548.1127815578. The cubic root of 42877781 is about 350.0075671833.

The spelling of 42877781 in words is "forty-two million, eight hundred seventy-seven thousand, seven hundred eighty-one".