161651555155611 has 8 divisors (see below), whose sum is σ = 239483785415760. Its totient is φ = 107767703437056.

The previous prime is 161651555155579. The next prime is 161651555155619. The reversal of 161651555155611 is 116551555156161.

161651555155611 is a `hidden beast` number, since 1 + 6 + 1 + 6 + 5 + 1 + 5 + 5 + 5 + 15 + 5 + 611 = 666.

It is not a de Polignac number, because 161651555155611 - 2⁵ = 161651555155579 is a prime.

It is a super-2 number, since 2×161651555155611² (a number of 29 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (161651555155619) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2993547317670 + ... + 2993547317723.

It is an arithmetic number, because the mean of its divisors is an integer number (29935473176970).

Almost surely, 2^{161651555155611} is an apocalyptic number.

161651555155611 is a deficient number, since it is larger than the sum of its proper divisors (77832230260149).

161651555155611 is an equidigital number, since it uses as much as digits as its factorization.

161651555155611 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5987094635402 (or 5987094635396 counting only the distinct ones).

The product of its digits is 3375000, while the sum is 54.

The spelling of 161651555155611 in words is "one hundred sixty-one trillion, six hundred fifty-one billion, five hundred fifty-five million, one hundred fifty-five thousand, six hundred eleven".