165521555061 has 8 divisors (see below), whose sum is σ = 221207462784. Its totient is φ = 110091675360.

The previous prime is 165521555009. The next prime is 165521555081. The reversal of 165521555061 is 160555125561.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-165521555061 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165521555081) 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, 64005496 + ... + 64008081.

It is an arithmetic number, because the mean of its divisors is an integer number (27650932848).

Almost surely, 2^165521555061 is an apocalyptic number.

It is an amenable number.

165521555061 is a deficient number, since it is larger than the sum of its proper divisors (55685907723).

165521555061 is a wasteful number, since it uses less digits than its factorization.

165521555061 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128014011.

The product of its (nonzero) digits is 225000, while the sum is 42.

The spelling of 165521555061 in words is "one hundred sixty-five billion, five hundred twenty-one million, five hundred fifty-five thousand, sixty-one".