661147058880 has 1512 divisors, whose sum is σ = 3003895440000. Its totient is φ = 132843110400.

The previous prime is 661147058863. The next prime is 661147058909. The reversal of 661147058880 is 88850741166.

It is a happy number.

661147058880 is a `hidden beast` number, since 6 + 6 + 11 + 47 + 0 + 588 + 8 + 0 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 215 ways as a sum of consecutive naturals, for example, 529340496 + ... + 529341744.

Almost surely, 2^661147058880 is an apocalyptic number.

661147058880 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 661147058880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1501947720000).

661147058880 is an abundant number, since it is smaller than the sum of its proper divisors (2342748381120).

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

661147058880 is a wasteful number, since it uses less digits than its factorization.

661147058880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1339 (or 1308 counting only the distinct ones).

The product of its (nonzero) digits is 2580480, while the sum is 54.

The spelling of 661147058880 in words is "six hundred sixty-one billion, one hundred forty-seven million, fifty-eight thousand, eight hundred eighty".