728775905431 has 4 divisors (see below), whose sum is σ = 832886749072. Its totient is φ = 624665061792.

The previous prime is 728775905423. The next prime is 728775905443. The reversal of 728775905431 is 134509577827.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 134509577827 = 59 ⋅2279823353.

It is a cyclic number.

It is not a de Polignac number, because 728775905431 - 2³ = 728775905423 is a prime.

It is a super-2 number, since 2×728775905431² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (728775905401) 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, 52055421810 + ... + 52055421823.

It is an arithmetic number, because the mean of its divisors is an integer number (208221687268).

Almost surely, 2^728775905431 is an apocalyptic number.

728775905431 is a deficient number, since it is larger than the sum of its proper divisors (104110843641).

728775905431 is a wasteful number, since it uses less digits than its factorization.

728775905431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 104110843640.

The product of its (nonzero) digits is 14817600, while the sum is 58.

The spelling of 728775905431 in words is "seven hundred twenty-eight billion, seven hundred seventy-five million, nine hundred five thousand, four hundred thirty-one".