66977909451 has 54 divisors (see below), whose sum is σ = 105893686860. Its totient is φ = 42244126992.

The previous prime is 66977909429. The next prime is 66977909533. The reversal of 66977909451 is 15490977966.

66977909451 is a `hidden beast` number, since 6 + 6 + 97 + 7 + 90 + 9 + 451 = 666.

It is not a de Polignac number, because 66977909451 - 2³⁴ = 49798040267 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66977409451) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 53 ways as a sum of consecutive naturals, for example, 91374681 + ... + 91375413.

Almost surely, 2^66977909451 is an apocalyptic number.

66977909451 is a deficient number, since it is larger than the sum of its proper divisors (38915777409).

66977909451 is an frugal number, since it uses more digits than its factorization.

66977909451 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1509 (or 755 counting only the distinct ones).

The product of its (nonzero) digits is 25719120, while the sum is 63.

The spelling of 66977909451 in words is "sixty-six billion, nine hundred seventy-seven million, nine hundred nine thousand, four hundred fifty-one".