40042081 has 4 divisors (see below), whose sum is σ = 40639792. Its totient is φ = 39444372.

The previous prime is 40042043. The next prime is 40042099. The reversal of 40042081 is 18024004.

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 a de Polignac number, because none of the positive numbers 2^k-40042081 is a prime.

It is a super-2 number, since 2×40042081² = 3206736501621122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (40042181) 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, 298755 + ... + 298888.

It is an arithmetic number, because the mean of its divisors is an integer number (10159948).

Almost surely, 2^40042081 is an apocalyptic number.

It is an amenable number.

40042081 is a deficient number, since it is larger than the sum of its proper divisors (597711).

40042081 is an equidigital number, since it uses as much as digits as its factorization.

40042081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 597710.

The product of its (nonzero) digits is 256, while the sum is 19.

The square root of 40042081 is about 6327.8812409842. The cubic root of 40042081 is about 342.1150764668.

Adding to 40042081 its reverse (18024004), we get a palindrome (58066085).

The spelling of 40042081 in words is "forty million, forty-two thousand, eighty-one".