661888641516067 has 16 divisors (see below), whose sum is σ = 767737754876160. Its totient is φ = 558863001040608.

The previous prime is 661888641516043. The next prime is 661888641516077. The reversal of 661888641516067 is 760615146888166.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-661888641516067 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (661888641516077) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 107683893 + ... + 113664409.

It is an arithmetic number, because the mean of its divisors is an integer number (47983609679760).

Almost surely, 2^{661888641516067} is an apocalyptic number.

661888641516067 is a gapful number since it is divisible by the number (67) formed by its first and last digit.

661888641516067 is a deficient number, since it is larger than the sum of its proper divisors (105849113360093).

661888641516067 is a wasteful number, since it uses less digits than its factorization.

661888641516067 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6216570.

The product of its (nonzero) digits is 557383680, while the sum is 73.

The spelling of 661888641516067 in words is "six hundred sixty-one trillion, eight hundred eighty-eight billion, six hundred forty-one million, five hundred sixteen thousand, sixty-seven".