40991951681 has 8 divisors (see below), whose sum is σ = 41206789800. Its totient is φ = 40777182208.

The previous prime is 40991951587. The next prime is 40991951699. The reversal of 40991951681 is 18615919904.

It can be written as a sum of positive squares in 4 ways, for example, as 28913941681 + 12078010000 = 170041^2 + 109900^2 .

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 40991951681 - 2¹⁴ = 40991935297 is a prime.

It is a super-2 number, since 2×40991951681² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (40991951281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1552865 + ... + 1579041.

It is an arithmetic number, because the mean of its divisors is an integer number (5150848725).

Almost surely, 2^40991951681 is an apocalyptic number.

It is an amenable number.

40991951681 is a deficient number, since it is larger than the sum of its proper divisors (214838119).

40991951681 is a wasteful number, since it uses less digits than its factorization.

40991951681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34323.

The product of its (nonzero) digits is 699840, while the sum is 53.

The spelling of 40991951681 in words is "forty billion, nine hundred ninety-one million, nine hundred fifty-one thousand, six hundred eighty-one".