66621172740000 has 240 divisors, whose sum is σ = 219468717179712. Its totient is φ = 17689394944000.

The previous prime is 66621172739959. The next prime is 66621172740013. The reversal of 66621172740000 is 4727112666.

It is a tau number, because it is divible by the number of its divisors (240).

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 11597269 + ... + 16362731.

Almost surely, 2^{66621172740000} is an apocalyptic number.

66621172740000 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 66621172740000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (109734358589856).

66621172740000 is an abundant number, since it is smaller than the sum of its proper divisors (152847544439712).

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

66621172740000 is a wasteful number, since it uses less digits than its factorization.

66621172740000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4765729 (or 4765706 counting only the distinct ones).

The product of its (nonzero) digits is 169344, while the sum is 42.

Adding to 66621172740000 its reverse (4727112666), we get a palindrome (66625899852666).

The spelling of 66621172740000 in words is "sixty-six trillion, six hundred twenty-one billion, one hundred seventy-two million, seven hundred forty thousand".