40047981 has 4 divisors (see below), whose sum is σ = 53397312. Its totient is φ = 26698652.

The previous prime is 40047979. The next prime is 40047983. The reversal of 40047981 is 18974004.

40047981 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 an interprime number because it is at equal distance from previous prime (40047979) and next prime (40047983).

It is a cyclic number.

It is not a de Polignac number, because 40047981 - 2¹ = 40047979 is a prime.

It is a super-2 number, since 2×40047981² = 3207681564352722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40047983) 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, 6674661 + ... + 6674666.

It is an arithmetic number, because the mean of its divisors is an integer number (13349328).

Almost surely, 2^40047981 is an apocalyptic number.

It is an amenable number.

40047981 is a deficient number, since it is larger than the sum of its proper divisors (13349331).

40047981 is a wasteful number, since it uses less digits than its factorization.

40047981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13349330.

The product of its (nonzero) digits is 8064, while the sum is 33.

The square root of 40047981 is about 6328.3474146099. The cubic root of 40047981 is about 342.1318786223.

The spelling of 40047981 in words is "forty million, forty-seven thousand, nine hundred eighty-one".