28061561 has 8 divisors (see below), whose sum is σ = 30656448. Its totient is φ = 25474000.

The previous prime is 28061557. The next prime is 28061569. The reversal of 28061561 is 16516082.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 28061561 - 2² = 28061557 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28061569) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8996 + ... + 11706.

It is an arithmetic number, because the mean of its divisors is an integer number (3832056).

Almost surely, 2^28061561 is an apocalyptic number.

It is an amenable number.

28061561 is a deficient number, since it is larger than the sum of its proper divisors (2594887).

28061561 is a wasteful number, since it uses less digits than its factorization.

28061561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3663.

The product of its (nonzero) digits is 2880, while the sum is 29.

The square root of 28061561 is about 5297.3163960632. The cubic root of 28061561 is about 303.8812764990.

The spelling of 28061561 in words is "twenty-eight million, sixty-one thousand, five hundred sixty-one".