28471989 has 48 divisors (see below), whose sum is σ = 48722688. Its totient is φ = 14652288.

The previous prime is 28471987. The next prime is 28472021. The reversal of 28471989 is 98917482.

It is not a de Polignac number, because 28471989 - 2¹ = 28471987 is a prime.

It is a super-2 number, since 2×28471989² = 1621308315232242, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28471987) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 89659 + ... + 89975.

It is an arithmetic number, because the mean of its divisors is an integer number (1015056).

Almost surely, 2^28471989 is an apocalyptic number.

It is an amenable number.

28471989 is a deficient number, since it is larger than the sum of its proper divisors (20250699).

28471989 is a wasteful number, since it uses less digits than its factorization.

28471989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 394 (or 387 counting only the distinct ones).

The product of its digits is 290304, while the sum is 48.

The square root of 28471989 is about 5335.9150105675. The cubic root of 28471989 is about 305.3556328251.

The spelling of 28471989 in words is "twenty-eight million, four hundred seventy-one thousand, nine hundred eighty-nine".