83121779442240 has 4032 divisors, whose sum is σ = 399191956300800. Its totient is φ = 15638792601600.

The previous prime is 83121779442239. The next prime is 83121779442319. The reversal of 83121779442240 is 4224497712138.

83121779442240 is a `hidden beast` number, since 8 + 3 + 1 + 2 + 177 + 9 + 4 + 422 + 40 = 666.

It is a tau number, because it is divible by the number of its divisors (4032).

It is an unprimeable number.

It is a polite number, since it can be written in 575 ways as a sum of consecutive naturals, for example, 64385575995 + ... + 64385577285.

Almost surely, 2^{83121779442240} is an apocalyptic number.

83121779442240 is a gapful number since it is divisible by the number (80) 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 83121779442240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (199595978150400).

83121779442240 is an abundant number, since it is smaller than the sum of its proper divisors (316070176858560).

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

83121779442240 is a wasteful number, since it uses less digits than its factorization.

83121779442240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1454 (or 1434 counting only the distinct ones).

The product of its (nonzero) digits is 5419008, while the sum is 54.

The spelling of 83121779442240 in words is "eighty-three trillion, one hundred twenty-one billion, seven hundred seventy-nine million, four hundred forty-two thousand, two hundred forty".