28131572866 has 8 divisors (see below), whose sum is σ = 42199458300. Its totient is φ = 14065086768.

The previous prime is 28131572863. The next prime is 28131572869. The reversal of 28131572866 is 66827513182.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (28131572863) and next prime (28131572869).

It can be written as a sum of positive squares in 2 ways, for example, as 17856709641 + 10274863225 = 133629^2 + 101365^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (28131572863) 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, 298041 + ... + 380908.

Almost surely, 2^28131572866 is an apocalyptic number.

28131572866 is a deficient number, since it is larger than the sum of its proper divisors (14067885434).

28131572866 is a wasteful number, since it uses less digits than its factorization.

28131572866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 699668.

The product of its digits is 967680, while the sum is 49.

The spelling of 28131572866 in words is "twenty-eight billion, one hundred thirty-one million, five hundred seventy-two thousand, eight hundred sixty-six".