15525561 has 4 divisors (see below), whose sum is σ = 20700752. Its totient is φ = 10350372.

The previous prime is 15525553. The next prime is 15525569. The reversal of 15525561 is 16552551.

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.

It is an interprime number because it is at equal distance from previous prime (15525553) and next prime (15525569).

It is not a de Polignac number, because 15525561 - 2³ = 15525553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15525569) 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, 2587591 + ... + 2587596.

It is an arithmetic number, because the mean of its divisors is an integer number (5175188).

Almost surely, 2^15525561 is an apocalyptic number.

It is an amenable number.

15525561 is a deficient number, since it is larger than the sum of its proper divisors (5175191).

15525561 is an equidigital number, since it uses as much as digits as its factorization.

15525561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5175190.

The product of its digits is 7500, while the sum is 30.

The square root of 15525561 is about 3940.2488500093. The cubic root of 15525561 is about 249.4685296243.

The spelling of 15525561 in words is "fifteen million, five hundred twenty-five thousand, five hundred sixty-one".