161609472 has 144 divisors (see below), whose sum is σ = 484673280. Its totient is φ = 53111808.

The previous prime is 161609471. The next prime is 161609473. The reversal of 161609472 is 274906161.

161609472 is a `hidden beast` number, since 1 + 6 + 1 + 609 + 47 + 2 = 666.

It is an interprime number because it is at equal distance from previous prime (161609471) and next prime (161609473).

It is a tau number, because it is divible by the number of its divisors (144).

It is a super-2 number, since 2×161609472² = 52235242880237568, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161609471) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 711823 + ... + 712049.

Almost surely, 2^161609472 is an apocalyptic number.

161609472 is a gapful number since it is divisible by the number (12) 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 161609472, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (242336640).

161609472 is an abundant number, since it is smaller than the sum of its proper divisors (323063808).

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

161609472 is a wasteful number, since it uses less digits than its factorization.

161609472 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 355 (or 335 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 36.

The square root of 161609472 is about 12712.5714157286. The cubic root of 161609472 is about 544.6977781780.

The spelling of 161609472 in words is "one hundred sixty-one million, six hundred nine thousand, four hundred seventy-two".