121778705664 has 1152 divisors, whose sum is σ = 474956267520. Its totient is φ = 30108672000.

The previous prime is 121778705647. The next prime is 121778705683. The reversal of 121778705664 is 466507877121.

121778705664 is a `hidden beast` number, since 1 + 2 + 1 + 7 + 7 + 8 + 70 + 566 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (1152).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a self number, because there is not a number n which added to its sum of digits gives 121778705664.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 1996372194 + ... + 1996372254.

Almost surely, 2^121778705664 is an apocalyptic number.

121778705664 is a gapful number since it is divisible by the number (14) 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 121778705664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (237478133760).

121778705664 is an abundant number, since it is smaller than the sum of its proper divisors (353177561856).

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

121778705664 is an equidigital number, since it uses as much as digits as its factorization.

121778705664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 157 (or 115 counting only the distinct ones).

The product of its (nonzero) digits is 3951360, while the sum is 54.

The spelling of 121778705664 in words is "one hundred twenty-one billion, seven hundred seventy-eight million, seven hundred five thousand, six hundred sixty-four".