42942981 has 4 divisors (see below), whose sum is σ = 57257312. Its totient is φ = 28628652.

The previous prime is 42942961. The next prime is 42942989. The reversal of 42942981 is 18924924.

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 de Polignac number, because none of the positive numbers 2^k-42942981 is a prime.

It is a super-2 number, since 2×42942981² = 3688199234332722, 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 (42942989) 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, 7157161 + ... + 7157166.

It is an arithmetic number, because the mean of its divisors is an integer number (14314328).

Almost surely, 2^42942981 is an apocalyptic number.

It is an amenable number.

42942981 is a deficient number, since it is larger than the sum of its proper divisors (14314331).

42942981 is a wasteful number, since it uses less digits than its factorization.

42942981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14314330.

The product of its digits is 41472, while the sum is 39.

The square root of 42942981 is about 6553.0894240808. The cubic root of 42942981 is about 350.1848846319.

The spelling of 42942981 in words is "forty-two million, nine hundred forty-two thousand, nine hundred eighty-one".