83721977 has 4 divisors (see below), whose sum is σ = 84255396. Its totient is φ = 83188560.

The previous prime is 83721949. The next prime is 83721997. The reversal of 83721977 is 77912738.

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

It can be written as a sum of positive squares in 2 ways, for example, as 62663056 + 21058921 = 7916^2 + 4589^2 .

It is a cyclic number.

It is not a de Polignac number, because 83721977 - 2¹⁴ = 83705593 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (83721907) 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, 266474 + ... + 266787.

It is an arithmetic number, because the mean of its divisors is an integer number (21063849).

Almost surely, 2^83721977 is an apocalyptic number.

It is an amenable number.

83721977 is a deficient number, since it is larger than the sum of its proper divisors (533419).

83721977 is a wasteful number, since it uses less digits than its factorization.

83721977 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 533418.

The product of its digits is 148176, while the sum is 44.

The square root of 83721977 is about 9149.9714207204. The cubic root of 83721977 is about 437.4682025326.

The spelling of 83721977 in words is "eighty-three million, seven hundred twenty-one thousand, nine hundred seventy-seven".