168645393540 has 144 divisors (see below), whose sum is σ = 551306316288. Its totient is φ = 41482720512.

The previous prime is 168645393529. The next prime is 168645393541. The reversal of 168645393540 is 45393546861.

168645393540 is a `hidden beast` number, since 1 + 6 + 8 + 6 + 4 + 5 + 3 + 93 + 540 = 666.

It is a super-2 number, since 2×168645393540² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (168645393541) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 3304497 + ... + 3355143.

Almost surely, 2^168645393540 is an apocalyptic number.

168645393540 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 168645393540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (275653158144).

168645393540 is an abundant number, since it is smaller than the sum of its proper divisors (382660922748).

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

168645393540 is a wasteful number, since it uses less digits than its factorization.

168645393540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52098 (or 52093 counting only the distinct ones).

The product of its (nonzero) digits is 9331200, while the sum is 54.

The spelling of 168645393540 in words is "one hundred sixty-eight billion, six hundred forty-five million, three hundred ninety-three thousand, five hundred forty".