66989624821 has 16 divisors (see below), whose sum is σ = 77495977728. Its totient is φ = 56720160000.

The previous prime is 66989624803. The next prime is 66989624899. The reversal of 66989624821 is 12842698966.

It is not a de Polignac number, because 66989624821 - 2¹⁵ = 66989592053 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 66989624821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66989624021) 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, 173271 + ... + 404971.

It is an arithmetic number, because the mean of its divisors is an integer number (4843498608).

Almost surely, 2^66989624821 is an apocalyptic number.

It is an amenable number.

66989624821 is a deficient number, since it is larger than the sum of its proper divisors (10506352907).

66989624821 is a wasteful number, since it uses less digits than its factorization.

66989624821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 232212.

The product of its digits is 17915904, while the sum is 61.

The spelling of 66989624821 in words is "sixty-six billion, nine hundred eighty-nine million, six hundred twenty-four thousand, eight hundred twenty-one".