40019881 has 4 divisors (see below), whose sum is σ = 43658064. Its totient is φ = 36381700.

The previous prime is 40019869. The next prime is 40019891. The reversal of 40019881 is 18891004.

40019881 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 40019881 - 2⁵ = 40019849 is a prime.

It is a super-2 number, since 2×40019881² = 3203181750508322, which contains 22 as substring.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (40019801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1819075 + ... + 1819096.

It is an arithmetic number, because the mean of its divisors is an integer number (10914516).

Almost surely, 2^40019881 is an apocalyptic number.

It is an amenable number.

40019881 is a deficient number, since it is larger than the sum of its proper divisors (3638183).

40019881 is a wasteful number, since it uses less digits than its factorization.

40019881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3638182.

The product of its (nonzero) digits is 2304, while the sum is 31.

The square root of 40019881 is about 6326.1268561419. The cubic root of 40019881 is about 342.0518400038.

It can be divided in two parts, 400 and 19881, that multiplied together give a square (7952400 = 2820²).

The spelling of 40019881 in words is "forty million, nineteen thousand, eight hundred eighty-one".