42946781 has 4 divisors (see below), whose sum is σ = 42965472. Its totient is φ = 42928092.

The previous prime is 42946759. The next prime is 42946789. The reversal of 42946781 is 18764924.

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 42946781 - 2²² = 38752477 is a prime.

It is a super-2 number, since 2×42946781² = 3688851996523922, 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 (42946789) 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, 5321 + ... + 10686.

It is an arithmetic number, because the mean of its divisors is an integer number (10741368).

Almost surely, 2^42946781 is an apocalyptic number.

It is an amenable number.

42946781 is a deficient number, since it is larger than the sum of its proper divisors (18691).

42946781 is a wasteful number, since it uses less digits than its factorization.

42946781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18690.

The product of its digits is 96768, while the sum is 41.

The square root of 42946781 is about 6553.3793572477. The cubic root of 42946781 is about 350.1952135478.

The spelling of 42946781 in words is "forty-two million, nine hundred forty-six thousand, seven hundred eighty-one".