17991901914840 has 768 divisors, whose sum is σ = 70171282022400. Its totient is φ = 3911809241088.

The previous prime is 17991901914809. The next prime is 17991901914907. The reversal of 17991901914840 is 4841910919971.

It is a super-2 number, since 2×17991901914840² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 5420878701 + ... + 5420882019.

It is an arithmetic number, because the mean of its divisors is an integer number (91368856800).

Almost surely, 2^{17991901914840} is an apocalyptic number.

17991901914840 is a gapful number since it is divisible by the number (10) 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 17991901914840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35085641011200).

17991901914840 is an abundant number, since it is smaller than the sum of its proper divisors (52179380107560).

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

17991901914840 is a wasteful number, since it uses less digits than its factorization.

17991901914840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4664 (or 4657 counting only the distinct ones).

The product of its (nonzero) digits is 5878656, while the sum is 63.

The spelling of 17991901914840 in words is "seventeen trillion, nine hundred ninety-one billion, nine hundred one million, nine hundred fourteen thousand, eight hundred forty".