28100121 has 8 divisors (see below), whose sum is σ = 42819264. Its totient is φ = 16057200.

The previous prime is 28100041. The next prime is 28100141. The reversal of 28100121 is 12100182.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 28100121 - 2¹⁸ = 27837977 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 28100121.

It is not an unprimeable number, because it can be changed into a prime (28100141) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 669030 + ... + 669071.

It is an arithmetic number, because the mean of its divisors is an integer number (5352408).

Almost surely, 2^28100121 is an apocalyptic number.

28100121 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

28100121 is a deficient number, since it is larger than the sum of its proper divisors (14719143).

28100121 is a wasteful number, since it uses less digits than its factorization.

28100121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1338111.

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

The square root of 28100121 is about 5300.9547253301. The cubic root of 28100121 is about 304.0204027454.

The spelling of 28100121 in words is "twenty-eight million, one hundred thousand, one hundred twenty-one".