1561878521280 has 1120 divisors, whose sum is σ = 7096125560832. Its totient is φ = 316613836800.

The previous prime is 1561878521279. The next prime is 1561878521293. The reversal of 1561878521280 is 821258781651.

It is a happy number.

1561878521280 is a `hidden beast` number, since 1 + 5 + 618 + 7 + 8 + 5 + 2 + 12 + 8 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (1120).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 81819897 + ... + 81838983.

Almost surely, 2^{1561878521280} is an apocalyptic number.

1561878521280 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 1561878521280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3548062780416).

1561878521280 is an abundant number, since it is smaller than the sum of its proper divisors (5534247039552).

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

1561878521280 is a wasteful number, since it uses less digits than its factorization.

1561878521280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19175 (or 19156 counting only the distinct ones).

The product of its (nonzero) digits is 2150400, while the sum is 54.

The spelling of 1561878521280 in words is "one trillion, five hundred sixty-one billion, eight hundred seventy-eight million, five hundred twenty-one thousand, two hundred eighty".