28061551 has 4 divisors (see below), whose sum is σ = 32070352. Its totient is φ = 24052752.

The previous prime is 28061519. The next prime is 28061557. The reversal of 28061551 is 15516082.

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

It is a cyclic number.

It is not a de Polignac number, because 28061551 - 2⁵ = 28061519 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 (28061557) 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, 2004390 + ... + 2004403.

It is an arithmetic number, because the mean of its divisors is an integer number (8017588).

Almost surely, 2^28061551 is an apocalyptic number.

28061551 is a deficient number, since it is larger than the sum of its proper divisors (4008801).

28061551 is an equidigital number, since it uses as much as digits as its factorization.

28061551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4008800.

The product of its (nonzero) digits is 2400, while the sum is 28.

The square root of 28061551 is about 5297.3154521890. The cubic root of 28061551 is about 303.8812404020.

The spelling of 28061551 in words is "twenty-eight million, sixty-one thousand, five hundred fifty-one".