66165623405 has 24 divisors (see below), whose sum is σ = 96377548032. Its totient is φ = 43398069792.

The previous prime is 66165623401. The next prime is 66165623429. The reversal of 66165623405 is 50432656166.

It is not a de Polignac number, because 66165623405 - 2² = 66165623401 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66165623401) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5865317 + ... + 5876586.

It is an arithmetic number, because the mean of its divisors is an integer number (4015731168).

Almost surely, 2^66165623405 is an apocalyptic number.

It is an amenable number.

66165623405 is a deficient number, since it is larger than the sum of its proper divisors (30211924627).

66165623405 is a wasteful number, since it uses less digits than its factorization.

66165623405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11741945 (or 11741938 counting only the distinct ones).

The product of its (nonzero) digits is 777600, while the sum is 44.

The spelling of 66165623405 in words is "sixty-six billion, one hundred sixty-five million, six hundred twenty-three thousand, four hundred five".