7728431 has 4 divisors (see below), whose sum is σ = 7738032. Its totient is φ = 7718832.

The previous prime is 7728403. The next prime is 7728439. The reversal of 7728431 is 1348277.

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: 1348277 = 7 ⋅192611.

It is a cyclic number.

It is not a de Polignac number, because 7728431 - 2⁶ = 7728367 is a prime.

It is a super-2 number, since 2×7728431² = 119457291443522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7728439) 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, 3470 + ... + 5243.

It is an arithmetic number, because the mean of its divisors is an integer number (1934508).

Almost surely, 2^7728431 is an apocalyptic number.

7728431 is a deficient number, since it is larger than the sum of its proper divisors (9601).

7728431 is an equidigital number, since it uses as much as digits as its factorization.

7728431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9600.

The product of its digits is 9408, while the sum is 32.

The square root of 7728431 is about 2780.0055755340. The cubic root of 7728431 is about 197.7108233176.

The spelling of 7728431 in words is "seven million, seven hundred twenty-eight thousand, four hundred thirty-one".