19401961680 has 240 divisors, whose sum is σ = 66056664960. Its totient is φ = 5102963712.

The previous prime is 19401961619. The next prime is 19401961693. The reversal of 19401961680 is 8616910491.

19401961680 is a `hidden beast` number, since 19 + 4 + 0 + 19 + 616 + 8 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (240).

It is a super-3 number, since 3×19401961680³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

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 pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 29441191 + ... + 29441849.

It is an arithmetic number, because the mean of its divisors is an integer number (275236104).

Almost surely, 2^19401961680 is an apocalyptic number.

19401961680 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 19401961680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33028332480).

19401961680 is an abundant number, since it is smaller than the sum of its proper divisors (46654703280).

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

19401961680 is a wasteful number, since it uses less digits than its factorization.

19401961680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1178 (or 1169 counting only the distinct ones).

The product of its (nonzero) digits is 93312, while the sum is 45.

The spelling of 19401961680 in words is "nineteen billion, four hundred one million, nine hundred sixty-one thousand, six hundred eighty".