165661061 has 4 divisors (see below), whose sum is σ = 165955872. Its totient is φ = 165366252.

The previous prime is 165661049. The next prime is 165661063. The reversal of 165661061 is 160166561.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 165661061 - 2⁶ = 165660997 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 (165661063) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 146561 + ... + 147686.

It is an arithmetic number, because the mean of its divisors is an integer number (41488968).

Almost surely, 2^165661061 is an apocalyptic number.

It is an amenable number.

165661061 is a deficient number, since it is larger than the sum of its proper divisors (294811).

165661061 is an equidigital number, since it uses as much as digits as its factorization.

165661061 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 294810.

The product of its (nonzero) digits is 6480, while the sum is 32.

The square root of 165661061 is about 12870.9386215614. The cubic root of 165661061 is about 549.2121623731.

The spelling of 165661061 in words is "one hundred sixty-five million, six hundred sixty-one thousand, sixty-one".