40515981 has 16 divisors (see below), whose sum is σ = 62399808. Its totient is φ = 23110400.

The previous prime is 40515971. The next prime is 40515989. The reversal of 40515981 is 18951504.

40515981 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 40515981 - 2⁹ = 40515469 is a prime.

It is a super-2 number, since 2×40515981² = 3283089432784722, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40515989) 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 15 ways as a sum of consecutive naturals, for example, 35550 + ... + 36671.

It is an arithmetic number, because the mean of its divisors is an integer number (3899988).

Almost surely, 2^40515981 is an apocalyptic number.

It is an amenable number.

40515981 is a deficient number, since it is larger than the sum of its proper divisors (21883827).

40515981 is a wasteful number, since it uses less digits than its factorization.

40515981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72252.

The product of its (nonzero) digits is 7200, while the sum is 33.

The square root of 40515981 is about 6365.2164927833. The cubic root of 40515981 is about 343.4594364022.

The spelling of 40515981 in words is "forty million, five hundred fifteen thousand, nine hundred eighty-one".