28915649 has 4 divisors (see below), whose sum is σ = 33046464. Its totient is φ = 24784836.

The previous prime is 28915643. The next prime is 28915693. The reversal of 28915649 is 94651982.

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 an emirpimes, since its reverse is a distinct semiprime: 94651982 = 2 ⋅47325991.

It is a cyclic number.

It is not a de Polignac number, because 28915649 - 2⁴ = 28915633 is a prime.

It is a super-2 number, since 2×28915649² = 1672229514182402, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28915643) 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, 2065397 + ... + 2065410.

It is an arithmetic number, because the mean of its divisors is an integer number (8261616).

Almost surely, 2^28915649 is an apocalyptic number.

It is an amenable number.

28915649 is a deficient number, since it is larger than the sum of its proper divisors (4130815).

28915649 is an equidigital number, since it uses as much as digits as its factorization.

28915649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4130814.

The product of its digits is 155520, while the sum is 44.

The square root of 28915649 is about 5377.3273101049. The cubic root of 28915649 is about 306.9335162863.

The spelling of 28915649 in words is "twenty-eight million, nine hundred fifteen thousand, six hundred forty-nine".