28390728961 has 16 divisors (see below), whose sum is σ = 33144330240. Its totient is φ = 23811806160.

The previous prime is 28390728907. The next prime is 28390728997. The reversal of 28390728961 is 16982709382.

It is a cyclic number.

It is not a de Polignac number, because 28390728961 - 2²⁹ = 27853858049 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28390720961) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2287270 + ... + 2299648.

It is an arithmetic number, because the mean of its divisors is an integer number (2071520640).

Almost surely, 2^28390728961 is an apocalyptic number.

It is an amenable number.

28390728961 is a deficient number, since it is larger than the sum of its proper divisors (4753601279).

28390728961 is a wasteful number, since it uses less digits than its factorization.

28390728961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19404.

The product of its (nonzero) digits is 2612736, while the sum is 55.

The spelling of 28390728961 in words is "twenty-eight billion, three hundred ninety million, seven hundred twenty-eight thousand, nine hundred sixty-one".