28771121 has 2 divisors, whose sum is σ = 28771122. Its totient is φ = 28771120.

The previous prime is 28771109. The next prime is 28771139. The reversal of 28771121 is 12117782.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17808400 + 10962721 = 4220^2 + 3311^2 .

It is a cyclic number.

It is not a de Polignac number, because 28771121 - 2¹⁰ = 28770097 is a prime.

It is not a weakly prime, because it can be changed into another prime (28771181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14385560 + 14385561.

It is an arithmetic number, because the mean of its divisors is an integer number (14385561).

Almost surely, 2^28771121 is an apocalyptic number.

It is an amenable number.

28771121 is a deficient number, since it is larger than the sum of its proper divisors (1).

28771121 is an equidigital number, since it uses as much as digits as its factorization.

28771121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1568, while the sum is 29.

The square root of 28771121 is about 5363.8718291920. The cubic root of 28771121 is about 306.4212838315.

The spelling of 28771121 in words is "twenty-eight million, seven hundred seventy-one thousand, one hundred twenty-one".