40991408640 has 1600 divisors, whose sum is σ = 192556425600. Its totient is φ = 8193540096.

The previous prime is 40991408617. The next prime is 40991408681. The reversal of 40991408640 is 4680419904.

40991408640 is a `hidden beast` number, since 409 + 91 + 40 + 86 + 40 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 2157442551 + ... + 2157442569.

It is an arithmetic number, because the mean of its divisors is an integer number (120347766).

Almost surely, 2^40991408640 is an apocalyptic number.

40991408640 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 40991408640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (96278212800).

40991408640 is an abundant number, since it is smaller than the sum of its proper divisors (151565016960).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

40991408640 is an equidigital number, since it uses as much as digits as its factorization.

40991408640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 92 (or 49 counting only the distinct ones).

The product of its (nonzero) digits is 248832, while the sum is 45.

The spelling of 40991408640 in words is "forty billion, nine hundred ninety-one million, four hundred eight thousand, six hundred forty".