77971933 has 4 divisors (see below), whose sum is σ = 83969788. Its totient is φ = 71974080.

The previous prime is 77971931. The next prime is 77971939. The reversal of 77971933 is 33917977.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 33917977 = 4523 ⋅7499.

It can be written as a sum of positive squares in 2 ways, for example, as 4235364 + 73736569 = 2058^2 + 8587^2 .

It is a cyclic number.

It is not a de Polignac number, because 77971933 - 2¹ = 77971931 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 (77971931) 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, 2998908 + ... + 2998933.

It is an arithmetic number, because the mean of its divisors is an integer number (20992447).

Almost surely, 2^77971933 is an apocalyptic number.

It is an amenable number.

77971933 is a deficient number, since it is larger than the sum of its proper divisors (5997855).

77971933 is a wasteful number, since it uses less digits than its factorization.

77971933 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5997854.

The product of its digits is 250047, while the sum is 46.

The square root of 77971933 is about 8830.1717423842. The cubic root of 77971933 is about 427.2146138544.

It can be divided in two parts, 7797 and 1933, that added together give a triangular number (9730 = T₁₃₉).

The spelling of 77971933 in words is "seventy-seven million, nine hundred seventy-one thousand, nine hundred thirty-three".