66155517054990 has 128 divisors (see below), whose sum is σ = 193023491581440. Its totient is φ = 15990111244800.

The previous prime is 66155517054931. The next prime is 66155517055003. The reversal of 66155517054990 is 9945071555166.

66155517054990 is a `hidden beast` number, since 6 + 6 + 1 + 5 + 551 + 70 + 5 + 4 + 9 + 9 + 0 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 32047456 + ... + 34049235.

It is an arithmetic number, because the mean of its divisors is an integer number (1507996027980).

Almost surely, 2^{66155517054990} is an apocalyptic number.

66155517054990 is an abundant number, since it is smaller than the sum of its proper divisors (126867974526450).

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

66155517054990 is a wasteful number, since it uses less digits than its factorization.

66155517054990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66097055 (or 66097049 counting only the distinct ones).

The product of its (nonzero) digits is 51030000, while the sum is 63.

The spelling of 66155517054990 in words is "sixty-six trillion, one hundred fifty-five billion, five hundred seventeen million, fifty-four thousand, nine hundred ninety".