15740561 has 4 divisors (see below), whose sum is σ = 15879972. Its totient is φ = 15601152.

The previous prime is 15740539. The next prime is 15740587. The reversal of 15740561 is 16504751.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16504751 = 1523 ⋅10837.

It can be written as a sum of positive squares in 2 ways, for example, as 6553600 + 9186961 = 2560^2 + 3031^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-15740561 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (15740161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 69536 + ... + 69761.

It is an arithmetic number, because the mean of its divisors is an integer number (3969993).

Almost surely, 2^15740561 is an apocalyptic number.

It is an amenable number.

15740561 is a deficient number, since it is larger than the sum of its proper divisors (139411).

15740561 is a wasteful number, since it uses less digits than its factorization.

15740561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 139410.

The product of its (nonzero) digits is 4200, while the sum is 29.

The square root of 15740561 is about 3967.4375861505. The cubic root of 15740561 is about 250.6148121181.

The spelling of 15740561 in words is "fifteen million, seven hundred forty thousand, five hundred sixty-one".