1961501384544 has 768 divisors, whose sum is σ = 6135766640640. Its totient is φ = 543449088000.

The previous prime is 1961501384543. The next prime is 1961501384551. The reversal of 1961501384544 is 4454831051691.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1961501384543) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 10837024134 + ... + 10837024314.

It is an arithmetic number, because the mean of its divisors is an integer number (7989279480).

Almost surely, 2^{1961501384544} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1961501384544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3067883320320).

1961501384544 is an abundant number, since it is smaller than the sum of its proper divisors (4174265256096).

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

1961501384544 is a wasteful number, since it uses less digits than its factorization.

1961501384544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 495 (or 487 counting only the distinct ones).

The product of its (nonzero) digits is 2073600, while the sum is 51.

The spelling of 1961501384544 in words is "one trillion, nine hundred sixty-one billion, five hundred one million, three hundred eighty-four thousand, five hundred forty-four".