28101021 has 16 divisors (see below), whose sum is σ = 40446336. Its totient is φ = 17251776.

The previous prime is 28101013. The next prime is 28101023. The reversal of 28101021 is 12010182.

It is not a de Polignac number, because 28101021 - 2³ = 28101013 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28101023) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 28096 + ... + 29078.

It is an arithmetic number, because the mean of its divisors is an integer number (2527896).

Almost surely, 2^28101021 is an apocalyptic number.

It is an amenable number.

28101021 is a deficient number, since it is larger than the sum of its proper divisors (12345315).

28101021 is a wasteful number, since it uses less digits than its factorization.

28101021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1732.

The product of its (nonzero) digits is 32, while the sum is 15.

The square root of 28101021 is about 5301.0396150189. The cubic root of 28101021 is about 304.0236484662.

The spelling of 28101021 in words is "twenty-eight million, one hundred one thousand, twenty-one".