161663840 has 48 divisors (see below), whose sum is σ = 411315408. Its totient is φ = 59690496.

The previous prime is 161663809. The next prime is 161663851. The reversal of 161663840 is 48366161.

161663840 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a super-3 number, since 3×161663840³ (a number of 26 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a self number, because there is not a number n which added to its sum of digits gives 161663840.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 36782 + ... + 40941.

It is an arithmetic number, because the mean of its divisors is an integer number (8569071).

Almost surely, 2^161663840 is an apocalyptic number.

161663840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161663840 is an abundant number, since it is smaller than the sum of its proper divisors (249651568).

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

161663840 is a wasteful number, since it uses less digits than its factorization.

161663840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77751 (or 77743 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 35.

The square root of 161663840 is about 12714.7095916501. The cubic root of 161663840 is about 544.7588529986.

It can be divided in two parts, 1616 and 63840, that added together give a palindrome (65456).

The spelling of 161663840 in words is "one hundred sixty-one million, six hundred sixty-three thousand, eight hundred forty".