1961409945600 has 2520 divisors, whose sum is σ = 8967168207360. Its totient is φ = 421382062080.

The previous prime is 1961409945587. The next prime is 1961409945623. The reversal of 1961409945600 is 65499041691.

1961409945600 is a `hidden beast` number, since 1 + 9 + 61 + 40 + 99 + 456 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (2520).

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

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 179 ways as a sum of consecutive naturals, for example, 15444172737 + ... + 15444172863.

Almost surely, 2^{1961409945600} is an apocalyptic number.

1961409945600 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 1961409945600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4483584103680).

1961409945600 is an abundant number, since it is smaller than the sum of its proper divisors (7005758261760).

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

1961409945600 is a wasteful number, since it uses less digits than its factorization.

1961409945600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 208 (or 163 counting only the distinct ones).

The product of its (nonzero) digits is 2099520, while the sum is 54.

The spelling of 1961409945600 in words is "one trillion, nine hundred sixty-one billion, four hundred nine million, nine hundred forty-five thousand, six hundred".