71728787 has 4 divisors (see below), whose sum is σ = 77246400. Its totient is φ = 66211176.

The previous prime is 71728777. The next prime is 71728799. The reversal of 71728787 is 78782717.

It is a happy number.

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 71728787 - 2⁴ = 71728771 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71728777) 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, 2758787 + ... + 2758812.

It is an arithmetic number, because the mean of its divisors is an integer number (19311600).

Almost surely, 2^71728787 is an apocalyptic number.

71728787 is a deficient number, since it is larger than the sum of its proper divisors (5517613).

71728787 is a wasteful number, since it uses less digits than its factorization.

71728787 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5517612.

The product of its digits is 307328, while the sum is 47.

The square root of 71728787 is about 8469.2849166857. The cubic root of 71728787 is about 415.4937501564.

The spelling of 71728787 in words is "seventy-one million, seven hundred twenty-eight thousand, seven hundred eighty-seven".