6645984121550 has 48 divisors (see below), whose sum is σ = 12525672055680. Its totient is φ = 2623172252640.

The previous prime is 6645984121549. The next prime is 6645984121613. The reversal of 6645984121550 is 551214895466.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2442521 + ... + 4388379.

It is an arithmetic number, because the mean of its divisors is an integer number (260951501160).

Almost surely, 2^{6645984121550} is an apocalyptic number.

6645984121550 is a deficient number, since it is larger than the sum of its proper divisors (5879687934130).

6645984121550 is a wasteful number, since it uses less digits than its factorization.

6645984121550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1946777 (or 1946772 counting only the distinct ones).

The product of its (nonzero) digits is 10368000, while the sum is 56.

The spelling of 6645984121550 in words is "six trillion, six hundred forty-five billion, nine hundred eighty-four million, one hundred twenty-one thousand, five hundred fifty".