28951728023761 has 3 divisors (see below), whose sum is σ = 28951733404443. Its totient is φ = 28951722643080.

The previous prime is 28951728023731. The next prime is 28951728023783. The reversal of 28951728023761 is 16732082715982.

It is a happy number.

The square root of 28951728023761 is 5380681.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 25529080022161 + 3422648001600 = 5052631^2 + 1850040^2 .

It is not a de Polignac number, because 28951728023761 - 2⁷ = 28951728023633 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28951728023761.

It is not an unprimeable number, because it can be changed into a prime (28951728023711) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 2690341 + ... + 8071021.

It is an arithmetic number, because the mean of its divisors is an integer number (9650577801481).

Almost surely, 2^{28951728023761} is an apocalyptic number.

28951728023761 is the 5380681-st square number.

28951728023761 is the 2690341-st centered octagonal number.

It is an amenable number.

28951728023761 is a deficient number, since it is larger than the sum of its proper divisors (5380682).

28951728023761 is an frugal number, since it uses more digits than its factorization.

28951728023761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10761362 (or 5380681 counting only the distinct ones).

The product of its (nonzero) digits is 20321280, while the sum is 61.

The spelling of 28951728023761 in words is "twenty-eight trillion, nine hundred fifty-one billion, seven hundred twenty-eight million, twenty-three thousand, seven hundred sixty-one".