40999991 has 4 divisors (see below), whose sum is σ = 41672184. Its totient is φ = 40327800.

The previous prime is 40999969. The next prime is 40999993. The reversal of 40999991 is 19999904.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 40999991 - 2¹⁸ = 40737847 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 (40999993) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 336005 + ... + 336126.

It is an arithmetic number, because the mean of its divisors is an integer number (10418046).

Almost surely, 2^40999991 is an apocalyptic number.

40999991 is a deficient number, since it is larger than the sum of its proper divisors (672193).

40999991 is an equidigital number, since it uses as much as digits as its factorization.

40999991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 672192.

The product of its (nonzero) digits is 236196, while the sum is 50.

The square root of 40999991 is about 6403.1235346509. The cubic root of 40999991 is about 344.8216988074.

The spelling of 40999991 in words is "forty million, nine hundred ninety-nine thousand, nine hundred ninety-one".