161501212125611 has 4 divisors (see below), whose sum is σ = 166710928645824. Its totient is φ = 156291495605400.

The previous prime is 161501212125571. The next prime is 161501212125623. The reversal of 161501212125611 is 116521212105161.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 161501212125611 - 2³⁸ = 161226334218667 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161501212125641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2604858260060 + ... + 2604858260121.

It is an arithmetic number, because the mean of its divisors is an integer number (41677732161456).

Almost surely, 2^{161501212125611} is an apocalyptic number.

161501212125611 is a deficient number, since it is larger than the sum of its proper divisors (5209716520213).

161501212125611 is an equidigital number, since it uses as much as digits as its factorization.

161501212125611 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5209716520212.

The product of its (nonzero) digits is 7200, while the sum is 35.

The spelling of 161501212125611 in words is "one hundred sixty-one trillion, five hundred one billion, two hundred twelve million, one hundred twenty-five thousand, six hundred eleven".