165521043 has 16 divisors (see below), whose sum is σ = 247975200. Its totient is φ = 109105920.

The previous prime is 165521039. The next prime is 165521047. The reversal of 165521043 is 340125561.

165521043 is a `hidden beast` number, since 1 + 6 + 552 + 104 + 3 = 666.

It is an interprime number because it is at equal distance from previous prime (165521039) and next prime (165521047).

It is not a de Polignac number, because 165521043 - 2² = 165521039 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a junction number, because it is equal to n+sod(n) for n = 165520998 and 165521016.

It is not an unprimeable number, because it can be changed into a prime (165521047) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32038 + ... + 36843.

It is an arithmetic number, because the mean of its divisors is an integer number (15498450).

Almost surely, 2^165521043 is an apocalyptic number.

165521043 is a deficient number, since it is larger than the sum of its proper divisors (82454157).

165521043 is an equidigital number, since it uses as much as digits as its factorization.

165521043 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68979 (or 68973 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 27.

The square root of 165521043 is about 12865.4981636935. The cubic root of 165521043 is about 549.0573859808.

The spelling of 165521043 in words is "one hundred sixty-five million, five hundred twenty-one thousand, forty-three".