72861977 has 4 divisors (see below), whose sum is σ = 72906036. Its totient is φ = 72817920.

The previous prime is 72861967. The next prime is 72862001. The reversal of 72861977 is 77916827.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 77916827 = 6359 ⋅12253.

It can be written as a sum of positive squares in 2 ways, for example, as 57093136 + 15768841 = 7556^2 + 3971^2 .

It is a cyclic number.

It is not a de Polignac number, because 72861977 - 2⁶ = 72861913 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72861947) 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 3 ways as a sum of consecutive naturals, for example, 19448 + ... + 22889.

It is an arithmetic number, because the mean of its divisors is an integer number (18226509).

Almost surely, 2^72861977 is an apocalyptic number.

It is an amenable number.

72861977 is a deficient number, since it is larger than the sum of its proper divisors (44059).

72861977 is a wasteful number, since it uses less digits than its factorization.

72861977 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44058.

The product of its digits is 296352, while the sum is 47.

The square root of 72861977 is about 8535.9227386382. The cubic root of 72861977 is about 417.6703539449.

The spelling of 72861977 in words is "seventy-two million, eight hundred sixty-one thousand, nine hundred seventy-seven".