28145961 has 14 divisors (see below), whose sum is σ = 42200730. Its totient is φ = 18763488.

The previous prime is 28145941. The next prime is 28145977. The reversal of 28145961 is 16954182.

It can be written as a sum of positive squares in only one way, i.e., 21566736 + 6579225 = 4644^2 + 2565^2 .

It is not a de Polignac number, because 28145961 - 2⁷ = 28145833 is a prime.

It is a super-2 number, since 2×28145961² = 1584390241227042, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28145911) by changing a digit.

It is a polite number, since it can be written in 13 ways as a sum of consecutive naturals, for example, 18576 + ... + 20033.

Almost surely, 2^28145961 is an apocalyptic number.

It is an amenable number.

28145961 is a deficient number, since it is larger than the sum of its proper divisors (14054769).

28145961 is an frugal number, since it uses more digits than its factorization.

28145961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38627 (or 38612 counting only the distinct ones).

The product of its digits is 17280, while the sum is 36.

The square root of 28145961 is about 5305.2767128586. The cubic root of 28145961 is about 304.1856300764.

The spelling of 28145961 in words is "twenty-eight million, one hundred forty-five thousand, nine hundred sixty-one".