28959921 has 24 divisors (see below), whose sum is σ = 45067776. Its totient is φ = 17867520.

The previous prime is 28959919. The next prime is 28959923. The reversal of 28959921 is 12995982.

It is an interprime number because it is at equal distance from previous prime (28959919) and next prime (28959923).

It is not a de Polignac number, because 28959921 - 2¹ = 28959919 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28959923) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4161 + ... + 8673.

It is an arithmetic number, because the mean of its divisors is an integer number (1877824).

Almost surely, 2^28959921 is an apocalyptic number.

It is an amenable number.

28959921 is a deficient number, since it is larger than the sum of its proper divisors (16107855).

28959921 is a wasteful number, since it uses less digits than its factorization.

28959921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4573 (or 4570 counting only the distinct ones).

The product of its digits is 116640, while the sum is 45.

The square root of 28959921 is about 5381.4422787948. The cubic root of 28959921 is about 307.0900823899.

The spelling of 28959921 in words is "twenty-eight million, nine hundred fifty-nine thousand, nine hundred twenty-one".