72143777 has 4 divisors (see below), whose sum is σ = 72209940. Its totient is φ = 72077616.

The previous prime is 72143761. The next prime is 72143803. The reversal of 72143777 is 77734127.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 77734127 = 7589 ⋅10243.

It can be written as a sum of positive squares in 2 ways, for example, as 1852321 + 70291456 = 1361^2 + 8384^2 .

It is a cyclic number.

It is not a de Polignac number, because 72143777 - 2⁴ = 72143761 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 72143777.

It is not an unprimeable number, because it can be changed into a prime (72143707) 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, 31418 + ... + 33635.

It is an arithmetic number, because the mean of its divisors is an integer number (18052485).

Almost surely, 2^72143777 is an apocalyptic number.

It is an amenable number.

72143777 is a deficient number, since it is larger than the sum of its proper divisors (66163).

72143777 is a wasteful number, since it uses less digits than its factorization.

72143777 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66162.

The product of its digits is 57624, while the sum is 38.

The square root of 72143777 is about 8493.7492899190. The cubic root of 72143777 is about 416.2934955014.

The spelling of 72143777 in words is "seventy-two million, one hundred forty-three thousand, seven hundred seventy-seven".