165821428801 has 8 divisors (see below), whose sum is σ = 189585100224. Its totient is φ = 142076481360.

The previous prime is 165821428793. The next prime is 165821428831. The reversal of 165821428801 is 108824128561.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 165821428801 - 2³ = 165821428793 is a prime.

It is a super-2 number, since 2×165821428801² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (165821428831) 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, 4662010 + ... + 4697443.

It is an arithmetic number, because the mean of its divisors is an integer number (23698137528).

Almost surely, 2^165821428801 is an apocalyptic number.

It is an amenable number.

165821428801 is a deficient number, since it is larger than the sum of its proper divisors (23763671423).

165821428801 is an equidigital number, since it uses as much as digits as its factorization.

165821428801 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9361991.

The product of its (nonzero) digits is 245760, while the sum is 46.

The spelling of 165821428801 in words is "one hundred sixty-five billion, eight hundred twenty-one million, four hundred twenty-eight thousand, eight hundred one".