2661853803840 has 3136 divisors, whose sum is σ = 13125435125760. Its totient is φ = 496628858880.

The previous prime is 2661853803821. The next prime is 2661853803901. The reversal of 2661853803840 is 483083581662.

2661853803840 is a `hidden beast` number, since 2 + 6 + 6 + 185 + 3 + 80 + 384 + 0 = 666.

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 447 ways as a sum of consecutive naturals, for example, 7023360771 + ... + 7023361149.

Almost surely, 2^{2661853803840} is an apocalyptic number.

2661853803840 is a gapful number since it is divisible by the number (20) 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 2661853803840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (6562717562880).

2661853803840 is an abundant number, since it is smaller than the sum of its proper divisors (10463581321920).

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

2661853803840 is a wasteful number, since it uses less digits than its factorization.

2661853803840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 472 (or 447 counting only the distinct ones).

The product of its (nonzero) digits is 6635520, while the sum is 54.

The spelling of 2661853803840 in words is "two trillion, six hundred sixty-one billion, eight hundred fifty-three million, eight hundred three thousand, eight hundred forty".