66943799961 has 16 divisors (see below), whose sum is σ = 89413039104. Its totient is φ = 44551929744.

The previous prime is 66943799959. The next prime is 66943799963. The reversal of 66943799961 is 16999734966.

66943799961 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (66943799959) and next prime (66943799963).

It is not a de Polignac number, because 66943799961 - 2¹ = 66943799959 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66943799963) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8704860 + ... + 8712546.

It is an arithmetic number, because the mean of its divisors is an integer number (5588314944).

Almost surely, 2^66943799961 is an apocalyptic number.

It is an amenable number.

66943799961 is a deficient number, since it is larger than the sum of its proper divisors (22469239143).

66943799961 is a wasteful number, since it uses less digits than its factorization.

66943799961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12340.

The product of its digits is 119042784, while the sum is 69.

The spelling of 66943799961 in words is "sixty-six billion, nine hundred forty-three million, seven hundred ninety-nine thousand, nine hundred sixty-one".