28100521 has 2 divisors, whose sum is σ = 28100522. Its totient is φ = 28100520.

The previous prime is 28100519. The next prime is 28100531. The reversal of 28100521 is 12500182.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19456921 + 8643600 = 4411^2 + 2940^2 .

It is a cyclic number.

It is not a de Polignac number, because 28100521 - 2¹ = 28100519 is a prime.

Together with 28100519, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (28100531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14050260 + 14050261.

It is an arithmetic number, because the mean of its divisors is an integer number (14050261).

Almost surely, 2^28100521 is an apocalyptic number.

It is an amenable number.

28100521 is a deficient number, since it is larger than the sum of its proper divisors (1).

28100521 is an equidigital number, since it uses as much as digits as its factorization.

28100521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 160, while the sum is 19.

The square root of 28100521 is about 5300.9924542485. The cubic root of 28100521 is about 304.0218452965.

The spelling of 28100521 in words is "twenty-eight million, one hundred thousand, five hundred twenty-one".