661483563289920 has 3584 divisors, whose sum is σ = 2954123550720000. Its totient is φ = 137633916026880.

The previous prime is 661483563289859. The next prime is 661483563289931. The reversal of 661483563289920 is 29982365384166.

661483563289920 is a `hidden beast` number, since 6 + 6 + 1 + 483 + 5 + 6 + 32 + 8 + 99 + 20 = 666.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 511 ways as a sum of consecutive naturals, for example, 726107094265 + ... + 726107095175.

Almost surely, 2^{661483563289920} is an apocalyptic number.

661483563289920 is a gapful number since it is divisible by the number (60) 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 661483563289920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1477061775360000).

661483563289920 is an abundant number, since it is smaller than the sum of its proper divisors (2292639987430080).

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

661483563289920 is a wasteful number, since it uses less digits than its factorization.

661483563289920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1273 (or 1245 counting only the distinct ones).

The product of its (nonzero) digits is 806215680, while the sum is 72.

The spelling of 661483563289920 in words is "six hundred sixty-one trillion, four hundred eighty-three billion, five hundred sixty-three million, two hundred eighty-nine thousand, nine hundred twenty".