28405901 has 4 divisors (see below), whose sum is σ = 28610400. Its totient is φ = 28201404.

The previous prime is 28405879. The next prime is 28405903. The reversal of 28405901 is 10950482.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 28405901 - 2¹⁸ = 28143757 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28405903) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 102041 + ... + 102318.

It is an arithmetic number, because the mean of its divisors is an integer number (7152600).

Almost surely, 2^28405901 is an apocalyptic number.

It is an amenable number.

28405901 is a deficient number, since it is larger than the sum of its proper divisors (204499).

28405901 is a wasteful number, since it uses less digits than its factorization.

28405901 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 204498.

The product of its (nonzero) digits is 2880, while the sum is 29.

The square root of 28405901 is about 5329.7186604923. The cubic root of 28405901 is about 305.1191901802.

The spelling of 28405901 in words is "twenty-eight million, four hundred five thousand, nine hundred one".