2017661515661 has 32 divisors (see below), whose sum is σ = 2227144550400. Its totient is φ = 1812680239680.

The previous prime is 2017661515643. The next prime is 2017661515711. The reversal of 2017661515661 is 1665151667102.

It is a cyclic number.

It is not a de Polignac number, because 2017661515661 - 2¹⁴ = 2017661499277 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2017661517661) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 236283530 + ... + 236292068.

It is an arithmetic number, because the mean of its divisors is an integer number (69598267200).

Almost surely, 2^{2017661515661} is an apocalyptic number.

It is an amenable number.

2017661515661 is a deficient number, since it is larger than the sum of its proper divisors (209483034739).

2017661515661 is a wasteful number, since it uses less digits than its factorization.

2017661515661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9449.

The product of its (nonzero) digits is 453600, while the sum is 47.

The spelling of 2017661515661 in words is "two trillion, seventeen billion, six hundred sixty-one million, five hundred fifteen thousand, six hundred sixty-one".