40555991 has 8 divisors (see below), whose sum is σ = 46828320. Its totient is φ = 34403328.

The previous prime is 40555987. The next prime is 40556003. The reversal of 40555991 is 19955504.

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

It is a cyclic number.

It is not a de Polignac number, because 40555991 - 2² = 40555987 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40555961) 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, 29186 + ... + 30543.

It is an arithmetic number, because the mean of its divisors is an integer number (5853540).

Almost surely, 2^40555991 is an apocalyptic number.

40555991 is a deficient number, since it is larger than the sum of its proper divisors (6272329).

40555991 is an equidigital number, since it uses as much as digits as its factorization.

40555991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59833.

The product of its (nonzero) digits is 40500, while the sum is 38.

The square root of 40555991 is about 6368.3585797284. The cubic root of 40555991 is about 343.5724559300.

The spelling of 40555991 in words is "forty million, five hundred fifty-five thousand, nine hundred ninety-one".