66617242477 has 4 divisors (see below), whose sum is σ = 66617821116. Its totient is φ = 66616663840.

The previous prime is 66617242453. The next prime is 66617242537. The reversal of 66617242477 is 77424271666.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 12136547556 + 54480694921 = 110166^2 + 233411^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66617242477 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 (66617242877) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 51424 + ... + 368617.

It is an arithmetic number, because the mean of its divisors is an integer number (16654455279).

Almost surely, 2^66617242477 is an apocalyptic number.

It is an amenable number.

66617242477 is a deficient number, since it is larger than the sum of its proper divisors (578639).

66617242477 is a wasteful number, since it uses less digits than its factorization.

66617242477 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 578638.

The product of its digits is 4741632, while the sum is 52.

The spelling of 66617242477 in words is "sixty-six billion, six hundred seventeen million, two hundred forty-two thousand, four hundred seventy-seven".