28115649131 has 4 divisors (see below), whose sum is σ = 28256934000. Its totient is φ = 27974364264.

The previous prime is 28115649127. The next prime is 28115649151. The reversal of 28115649131 is 13194651182.

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: 13194651182 = 2 ⋅6597325591.

It is a cyclic number.

It is not a de Polignac number, because 28115649131 - 2² = 28115649127 is a prime.

It is a super-2 number, since 2×28115649131² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28115649151) 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, 70642136 + ... + 70642533.

It is an arithmetic number, because the mean of its divisors is an integer number (7064233500).

Almost surely, 2^28115649131 is an apocalyptic number.

28115649131 is a deficient number, since it is larger than the sum of its proper divisors (141284869).

28115649131 is a wasteful number, since it uses less digits than its factorization.

28115649131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 141284868.

The product of its digits is 51840, while the sum is 41.

The spelling of 28115649131 in words is "twenty-eight billion, one hundred fifteen million, six hundred forty-nine thousand, one hundred thirty-one".