28215541 has 2 divisors, whose sum is σ = 28215542. Its totient is φ = 28215540.

The previous prime is 28215527. The next prime is 28215559. The reversal of 28215541 is 14551282.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 23716900 + 4498641 = 4870^2 + 2121^2 .

It is a cyclic number.

It is not a de Polignac number, because 28215541 - 2⁹ = 28215029 is a prime.

It is a super-2 number, since 2×28215541² = 1592233507845362, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28210541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14107770 + 14107771.

It is an arithmetic number, because the mean of its divisors is an integer number (14107771).

Almost surely, 2^28215541 is an apocalyptic number.

It is an amenable number.

28215541 is a deficient number, since it is larger than the sum of its proper divisors (1).

28215541 is an equidigital number, since it uses as much as digits as its factorization.

28215541 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3200, while the sum is 28.

The square root of 28215541 is about 5311.8302871986. The cubic root of 28215541 is about 304.4360842369.

The spelling of 28215541 in words is "twenty-eight million, two hundred fifteen thousand, five hundred forty-one".