15541609 has 2 divisors, whose sum is σ = 15541610. Its totient is φ = 15541608.

The previous prime is 15541597. The next prime is 15541637. The reversal of 15541609 is 90614551.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12981609 + 2560000 = 3603^2 + 1600^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-15541609 is a prime.

It is a super-2 number, since 2×15541609² = 483083220617762, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (15541649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7770804 + 7770805.

It is an arithmetic number, because the mean of its divisors is an integer number (7770805).

Almost surely, 2^15541609 is an apocalyptic number.

It is an amenable number.

15541609 is a deficient number, since it is larger than the sum of its proper divisors (1).

15541609 is an equidigital number, since it uses as much as digits as its factorization.

15541609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5400, while the sum is 31.

The square root of 15541609 is about 3942.2847436480. The cubic root of 15541609 is about 249.5544544283.

The spelling of 15541609 in words is "fifteen million, five hundred forty-one thousand, six hundred nine".