728708469781 has 4 divisors (see below), whose sum is σ = 760391446752. Its totient is φ = 697025492812.

The previous prime is 728708469763. The next prime is 728708469799. The reversal of 728708469781 is 187964807827.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (728708469763) and next prime (728708469799).

It is a cyclic number.

It is not a de Polignac number, because 728708469781 - 2²³ = 728700081173 is a prime.

It is a super-2 number, since 2×728708469781² (a number of 25 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (67) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (728708469721) 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, 15841488451 + ... + 15841488496.

It is an arithmetic number, because the mean of its divisors is an integer number (190097861688).

Almost surely, 2^728708469781 is an apocalyptic number.

It is an amenable number.

728708469781 is a deficient number, since it is larger than the sum of its proper divisors (31682976971).

728708469781 is a wasteful number, since it uses less digits than its factorization.

728708469781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31682976970.

The product of its (nonzero) digits is 75866112, while the sum is 67.

The spelling of 728708469781 in words is "seven hundred twenty-eight billion, seven hundred eight million, four hundred sixty-nine thousand, seven hundred eighty-one".