28197541 has 4 divisors (see below), whose sum is σ = 29169900. Its totient is φ = 27225184.

The previous prime is 28197529. The next prime is 28197557. The reversal of 28197541 is 14579182.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 20657025 + 7540516 = 4545^2 + 2746^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28197541 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28197541.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28197511) 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, 486136 + ... + 486193.

It is an arithmetic number, because the mean of its divisors is an integer number (7292475).

Almost surely, 2^28197541 is an apocalyptic number.

It is an amenable number.

28197541 is a deficient number, since it is larger than the sum of its proper divisors (972359).

28197541 is an equidigital number, since it uses as much as digits as its factorization.

28197541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 972358.

The product of its digits is 20160, while the sum is 37.

The square root of 28197541 is about 5310.1356856487. The cubic root of 28197541 is about 304.3713325077.

The spelling of 28197541 in words is "twenty-eight million, one hundred ninety-seven thousand, five hundred forty-one".