40947991 has 8 divisors (see below), whose sum is σ = 47390720. Its totient is φ = 34653528.

The previous prime is 40947989. The next prime is 40948001. The reversal of 40947991 is 19974904.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 40947991 - 2¹ = 40947989 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40947691) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 36471 + ... + 37576.

It is an arithmetic number, because the mean of its divisors is an integer number (5923840).

Almost surely, 2^40947991 is an apocalyptic number.

40947991 is the 3695-th hex number.

40947991 is a deficient number, since it is larger than the sum of its proper divisors (6442729).

40947991 is an equidigital number, since it uses as much as digits as its factorization.

40947991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74133.

The product of its (nonzero) digits is 81648, while the sum is 43.

The square root of 40947991 is about 6399.0617280973. The cubic root of 40947991 is about 344.6758588229.

It can be divided in two parts, 409 and 47991, that added together give a square (48400 = 220²).

The spelling of 40947991 in words is "forty million, nine hundred forty-seven thousand, nine hundred ninety-one".