166918400737780 has 48 divisors (see below), whose sum is σ = 350586609745680. Its totient is φ = 66756319838208.

The previous prime is 166918400737717. The next prime is 166918400737789. The reversal of 166918400737780 is 87737004819661.

It can be written as a sum of positive squares in 8 ways, for example, as 188172028944 + 166730228708836 = 433788^2 + 12912406^2 .

It is a super-2 number, since 2×166918400737780² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166918400737789) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4245863404 + ... + 4245902716.

It is an arithmetic number, because the mean of its divisors is an integer number (7303887703035).

Almost surely, 2^{166918400737780} is an apocalyptic number.

166918400737780 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

166918400737780 is an abundant number, since it is smaller than the sum of its proper divisors (183668209007900).

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

166918400737780 is a wasteful number, since it uses less digits than its factorization.

166918400737780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69028 (or 69026 counting only the distinct ones).

The product of its (nonzero) digits is 85349376, while the sum is 67.

The spelling of 166918400737780 in words is "one hundred sixty-six trillion, nine hundred eighteen billion, four hundred million, seven hundred thirty-seven thousand, seven hundred eighty".