28121976 has 96 divisors (see below), whose sum is σ = 81728400. Its totient is φ = 8709120.

The previous prime is 28121969. The next prime is 28121983. The reversal of 28121976 is 67912182.

28121976 = 104² + 105² + ... + 440².

It is an interprime number because it is at equal distance from previous prime (28121969) and next prime (28121983).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 28121976.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 83280 + ... + 83616.

Almost surely, 2^28121976 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28121976, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40864200).

28121976 is an abundant number, since it is smaller than the sum of its proper divisors (53606424).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28121976 is a wasteful number, since it uses less digits than its factorization.

28121976 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 429 (or 422 counting only the distinct ones).

The product of its digits is 12096, while the sum is 36.

The square root of 28121976 is about 5303.0157457809. The cubic root of 28121976 is about 304.0992000820.

The spelling of 28121976 in words is "twenty-eight million, one hundred twenty-one thousand, nine hundred seventy-six".