66621406776 has 16 divisors (see below), whose sum is σ = 166553517000. Its totient is φ = 22207135584.

The previous prime is 66621406741. The next prime is 66621406799. The reversal of 66621406776 is 67760412666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1387945951 + ... + 1387945998.

Almost surely, 2^66621406776 is an apocalyptic number.

It is an amenable number.

66621406776 is an abundant number, since it is smaller than the sum of its proper divisors (99932110224).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66621406776 is a wasteful number, since it uses less digits than its factorization.

66621406776 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2775891958 (or 2775891954 counting only the distinct ones).

The product of its (nonzero) digits is 3048192, while the sum is 51.

The spelling of 66621406776 in words is "sixty-six billion, six hundred twenty-one million, four hundred six thousand, seven hundred seventy-six".