661898652000 has 288 divisors, whose sum is σ = 2192816362464. Its totient is φ = 174522240000.

The previous prime is 661898651969. The next prime is 661898652007. The reversal of 661898652000 is 256898166.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661898652007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 895667631 + ... + 895668369.

It is an arithmetic number, because the mean of its divisors is an integer number (7613945703).

Almost surely, 2^661898652000 is an apocalyptic number.

661898652000 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 661898652000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1096408181232).

661898652000 is an abundant number, since it is smaller than the sum of its proper divisors (1530917710464).

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

661898652000 is an equidigital number, since it uses as much as digits as its factorization.

661898652000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1607 (or 850 counting only the distinct ones).

The product of its (nonzero) digits is 1244160, while the sum is 51.

The spelling of 661898652000 in words is "six hundred sixty-one billion, eight hundred ninety-eight million, six hundred fifty-two thousand".