1861861697280 has 1080 divisors, whose sum is σ = 7340314156560. Its totient is φ = 450286387200.

The previous prime is 1861861697263. The next prime is 1861861697291. The reversal of 1861861697280 is 827961681681.

1861861697280 is a `hidden beast` number, since 1 + 8 + 6 + 1 + 8 + 616 + 9 + 7 + 2 + 8 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (1080).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 1033792380 + ... + 1033794180.

It is an arithmetic number, because the mean of its divisors is an integer number (6796587182).

Almost surely, 2^{1861861697280} is an apocalyptic number.

1861861697280 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 1861861697280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3670157078280).

1861861697280 is an abundant number, since it is smaller than the sum of its proper divisors (5478452459280).

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

1861861697280 is a wasteful number, since it uses less digits than its factorization.

1861861697280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1919 (or 1883 counting only the distinct ones).

The product of its (nonzero) digits is 13934592, while the sum is 63.

The spelling of 1861861697280 in words is "one trillion, eight hundred sixty-one billion, eight hundred sixty-one million, six hundred ninety-seven thousand, two hundred eighty".