28165667500621 has 6 divisors (see below), whose sum is σ = 32764143827310. Its totient is φ = 24142000714776.

The previous prime is 28165667500571. The next prime is 28165667500679. The reversal of 28165667500621 is 12600576656182.

It can be written as a sum of positive squares in only one way, i.e., 24639012612900 + 3526654887721 = 4963770^2 + 1877939^2 .

It is not a de Polignac number, because 28165667500621 - 2¹³ = 28165667492429 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28165667500121) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 287404770366 + ... + 287404770463.

It is an arithmetic number, because the mean of its divisors is an integer number (5460690637885).

Almost surely, 2^{28165667500621} is an apocalyptic number.

It is an amenable number.

28165667500621 is a deficient number, since it is larger than the sum of its proper divisors (4598476326689).

28165667500621 is an equidigital number, since it uses as much as digits as its factorization.

28165667500621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 574809540843 (or 574809540836 counting only the distinct ones).

The product of its (nonzero) digits is 7257600, while the sum is 55.

The spelling of 28165667500621 in words is "twenty-eight trillion, one hundred sixty-five billion, six hundred sixty-seven million, five hundred thousand, six hundred twenty-one".