1611601615565 has 16 divisors (see below), whose sum is σ = 1957743986688. Its totient is φ = 1273452781056.

The previous prime is 1611601615543. The next prime is 1611601615567. The reversal of 1611601615565 is 5655161061161.

It is a cyclic number.

It is not a de Polignac number, because 1611601615565 - 2¹⁶ = 1611601550029 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1611601615567) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3059117 + ... + 3547026.

It is an arithmetic number, because the mean of its divisors is an integer number (122358999168).

Almost surely, 2^{1611601615565} is an apocalyptic number.

It is an amenable number.

1611601615565 is a deficient number, since it is larger than the sum of its proper divisors (346142371123).

1611601615565 is an equidigital number, since it uses as much as digits as its factorization.

1611601615565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6606748.

The product of its (nonzero) digits is 162000, while the sum is 44.

The spelling of 1611601615565 in words is "one trillion, six hundred eleven billion, six hundred one million, six hundred fifteen thousand, five hundred sixty-five".