28016641 has 4 divisors (see below), whose sum is σ = 28028592. Its totient is φ = 28004692.

The previous prime is 28016633. The next prime is 28016657. The reversal of 28016641 is 14661082.

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, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 14661082 = 2 ⋅7330541.

It is a cyclic number.

It is not a de Polignac number, because 28016641 - 2³ = 28016633 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28016041) 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, 1171 + ... + 7576.

It is an arithmetic number, because the mean of its divisors is an integer number (7007148).

It is a Proth number, since it is equal to 855 ⋅ 2¹⁵ + 1 and 855 < 2¹⁵.

Almost surely, 2^28016641 is an apocalyptic number.

It is an amenable number.

28016641 is a deficient number, since it is larger than the sum of its proper divisors (11951).

28016641 is an equidigital number, since it uses as much as digits as its factorization.

28016641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11950.

The product of its (nonzero) digits is 2304, while the sum is 28.

The square root of 28016641 is about 5293.0748152657. The cubic root of 28016641 is about 303.7190422705.

The spelling of 28016641 in words is "twenty-eight million, sixteen thousand, six hundred forty-one".