28981901 has 16 divisors (see below), whose sum is σ = 31951920. Its totient is φ = 26127360.

The previous prime is 28981891. The next prime is 28981907. The reversal of 28981901 is 10918982.

It can be written as a sum of positive squares in 8 ways, for example, as 13764100 + 15217801 = 3710^2 + 3901^2 .

It is a cyclic number.

It is not a de Polignac number, because 28981901 - 2⁶ = 28981837 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 (28981907) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 160031 + ... + 160211.

It is an arithmetic number, because the mean of its divisors is an integer number (1996995).

Almost surely, 2^28981901 is an apocalyptic number.

It is an amenable number.

28981901 is a deficient number, since it is larger than the sum of its proper divisors (2970019).

28981901 is a wasteful number, since it uses less digits than its factorization.

28981901 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 416.

The product of its (nonzero) digits is 10368, while the sum is 38.

The square root of 28981901 is about 5383.4840948962. The cubic root of 28981901 is about 307.1677544833.

The spelling of 28981901 in words is "twenty-eight million, nine hundred eighty-one thousand, nine hundred one".