28055261 has 4 divisors (see below), whose sum is σ = 30213372. Its totient is φ = 25897152.

The previous prime is 28055257. The next prime is 28055273. The reversal of 28055261 is 16255082.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16255082 = 2 ⋅8127541.

It can be written as a sum of positive squares in 2 ways, for example, as 12602500 + 15452761 = 3550^2 + 3931^2 .

It is a cyclic number.

It is not a de Polignac number, because 28055261 - 2² = 28055257 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28055201) 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, 1079036 + ... + 1079061.

It is an arithmetic number, because the mean of its divisors is an integer number (7553343).

Almost surely, 2^28055261 is an apocalyptic number.

It is an amenable number.

28055261 is a deficient number, since it is larger than the sum of its proper divisors (2158111).

28055261 is a wasteful number, since it uses less digits than its factorization.

28055261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2158110.

The product of its (nonzero) digits is 4800, while the sum is 29.

The square root of 28055261 is about 5296.7217219711. The cubic root of 28055261 is about 303.8585336999.

The spelling of 28055261 in words is "twenty-eight million, fifty-five thousand, two hundred sixty-one".