728784761 has 4 divisors (see below), whose sum is σ = 753915300. Its totient is φ = 703654224.

The previous prime is 728784743. The next prime is 728784779. The reversal of 728784761 is 167487827.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (728784743) and next prime (728784779).

It can be written as a sum of positive squares in 2 ways, for example, as 336942736 + 391842025 = 18356^2 + 19795^2 .

It is a cyclic number.

It is not a de Polignac number, because 728784761 - 2¹⁸ = 728522617 is a prime.

It is a super-2 number, since 2×728784761² = 1062254455731654242, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (728784701) 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, 12565226 + ... + 12565283.

It is an arithmetic number, because the mean of its divisors is an integer number (188478825).

Almost surely, 2^728784761 is an apocalyptic number.

It is an amenable number.

728784761 is a deficient number, since it is larger than the sum of its proper divisors (25130539).

728784761 is a wasteful number, since it uses less digits than its factorization.

728784761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25130538.

The product of its digits is 1053696, while the sum is 50.

The square root of 728784761 is about 26996.0137983370. The cubic root of 728784761 is about 899.9114155610.

The spelling of 728784761 in words is "seven hundred twenty-eight million, seven hundred eighty-four thousand, seven hundred sixty-one".