66977851 has 4 divisors (see below), whose sum is σ = 67044600. Its totient is φ = 66911104.

The previous prime is 66977839. The next prime is 66977857. The reversal of 66977851 is 15877966.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 66977851 - 2⁵ = 66977819 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 66977795 and 66977804.

It is not an unprimeable number, because it can be changed into a prime (66977857) 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, 31846 + ... + 33883.

It is an arithmetic number, because the mean of its divisors is an integer number (16761150).

Almost surely, 2^66977851 is an apocalyptic number.

66977851 is a deficient number, since it is larger than the sum of its proper divisors (66749).

66977851 is a wasteful number, since it uses less digits than its factorization.

66977851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66748.

The product of its digits is 635040, while the sum is 49.

The square root of 66977851 is about 8183.9996945259. Note that the first 3 decimals coincide. The cubic root of 66977851 is about 406.1100492766.

The spelling of 66977851 in words is "sixty-six million, nine hundred seventy-seven thousand, eight hundred fifty-one".