2661554609280 has 1920 divisors, whose sum is σ = 11839848451200. Its totient is φ = 557702184960.

The previous prime is 2661554609251. The next prime is 2661554609291. The reversal of 2661554609280 is 829064551662.

2661554609280 is a `hidden beast` number, since 2 + 6 + 6 + 1 + 5 + 5 + 4 + 609 + 28 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (1920).

It is a super-2 number, since 2×2661554609280² (a number of 26 digits) contains 22 as substring.

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 239 ways as a sum of consecutive naturals, for example, 4299764811 + ... + 4299765429.

It is an arithmetic number, because the mean of its divisors is an integer number (6166587735).

Almost surely, 2^{2661554609280} is an apocalyptic number.

2661554609280 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 2661554609280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (5919924225600).

2661554609280 is an abundant number, since it is smaller than the sum of its proper divisors (9178293841920).

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

2661554609280 is a wasteful number, since it uses less digits than its factorization.

2661554609280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 732 (or 694 counting only the distinct ones).

The product of its (nonzero) digits is 6220800, while the sum is 54.

The spelling of 2661554609280 in words is "two trillion, six hundred sixty-one billion, five hundred fifty-four million, six hundred nine thousand, two hundred eighty".