165404890 has 60 divisors (see below), whose sum is σ = 351564714. Its totient is φ = 56026992.

The previous prime is 165404887. The next prime is 165404909. The reversal of 165404890 is 98404561.

It is a happy number.

165404890 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 148864401 + 16540489 = 12201^2 + 4067^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 1992789 + ... + 1992871.

Almost surely, 2^165404890 is an apocalyptic number.

165404890 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

165404890 is an abundant number, since it is smaller than the sum of its proper divisors (186159824).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

165404890 is an frugal number, since it uses more digits than its factorization.

165404890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 201 (or 97 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 37.

The square root of 165404890 is about 12860.9832439048. The cubic root of 165404890 is about 548.9289237926.

The spelling of 165404890 in words is "one hundred sixty-five million, four hundred four thousand, eight hundred ninety".