165540540 has 192 divisors, whose sum is σ = 546416640. Its totient is φ = 37013760.

The previous prime is 165540511. The next prime is 165540581. The reversal of 165540540 is 45045561.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 165540498 and 165540507.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 539067 + ... + 539373.

It is an arithmetic number, because the mean of its divisors is an integer number (2845920).

Almost surely, 2^165540540 is an apocalyptic number.

165540540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 165540540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (273208320).

165540540 is an abundant number, since it is smaller than the sum of its proper divisors (380876100).

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

165540540 is a wasteful number, since it uses less digits than its factorization.

165540540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 392 (or 390 counting only the distinct ones).

The product of its (nonzero) digits is 12000, while the sum is 30.

The square root of 165540540 is about 12866.2558656355. The cubic root of 165540540 is about 549.0789432631.

It can be divided in two parts, 1655 and 40540, that added together give a triangular number (42195 = T₂₉₀).

The spelling of 165540540 in words is "one hundred sixty-five million, five hundred forty thousand, five hundred forty".