15661057 has 4 divisors (see below), whose sum is σ = 16043076. Its totient is φ = 15279040.

The previous prime is 15661033. The next prime is 15661069. The reversal of 15661057 is 75016651.

15661057 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 75016651 = 103 ⋅728317.

It can be written as a sum of positive squares in 2 ways, for example, as 6230016 + 9431041 = 2496^2 + 3071^2 .

It is a cyclic number.

It is not a de Polignac number, because 15661057 - 2⁷ = 15660929 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15661007) 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, 190948 + ... + 191029.

It is an arithmetic number, because the mean of its divisors is an integer number (4010769).

Almost surely, 2^15661057 is an apocalyptic number.

It is an amenable number.

15661057 is a deficient number, since it is larger than the sum of its proper divisors (382019).

15661057 is an equidigital number, since it uses as much as digits as its factorization.

15661057 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 382018.

The product of its (nonzero) digits is 6300, while the sum is 31.

The square root of 15661057 is about 3957.4053368337. The cubic root of 15661057 is about 250.1921562660.

The spelling of 15661057 in words is "fifteen million, six hundred sixty-one thousand, fifty-seven".