66977931 has 8 divisors (see below), whose sum is σ = 89590480. Its totient is φ = 44508672.

The previous prime is 66977923. The next prime is 66977951. The reversal of 66977931 is 13977966.

66977931 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 66977931 - 2³ = 66977923 is a prime.

It is a super-3 number, since 3×66977931³ (a number of 24 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66977951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 34726 + ... + 36603.

It is an arithmetic number, because the mean of its divisors is an integer number (11198810).

Almost surely, 2^66977931 is an apocalyptic number.

66977931 is a deficient number, since it is larger than the sum of its proper divisors (22612549).

66977931 is a wasteful number, since it uses less digits than its factorization.

66977931 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71645.

The product of its digits is 428652, while the sum is 48.

The square root of 66977931 is about 8184.0045821102. The cubic root of 66977931 is about 406.1102109658.

The spelling of 66977931 in words is "sixty-six million, nine hundred seventy-seven thousand, nine hundred thirty-one".