66961510987 has 8 divisors (see below), whose sum is σ = 81029055456. Its totient is φ = 54019370112.

The previous prime is 66961510981. The next prime is 66961510991. The reversal of 66961510987 is 78901516966.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66961510987 - 2¹⁵ = 66961478219 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66961510981) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 281350768 + ... + 281351005.

It is an arithmetic number, because the mean of its divisors is an integer number (10128631932).

Almost surely, 2^66961510987 is an apocalyptic number.

66961510987 is a deficient number, since it is larger than the sum of its proper divisors (14067544469).

66961510987 is a wasteful number, since it uses less digits than its factorization.

66961510987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 562701797.

The product of its (nonzero) digits is 4898880, while the sum is 58.

The spelling of 66961510987 in words is "sixty-six billion, nine hundred sixty-one million, five hundred ten thousand, nine hundred eighty-seven".