161617572 has 192 divisors, whose sum is σ = 482630400. Its totient is φ = 46448640.

The previous prime is 161617571. The next prime is 161617627. The reversal of 161617572 is 275716161.

It is a super-2 number, since 2×161617572² = 52240479158350368, which contains 22 as substring.

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

It is not an unprimeable number, because it can be changed into a prime (161617571) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1430188 + ... + 1430300.

It is an arithmetic number, because the mean of its divisors is an integer number (2513700).

Almost surely, 2^161617572 is an apocalyptic number.

161617572 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 161617572, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (241315200).

161617572 is an abundant number, since it is smaller than the sum of its proper divisors (321012828).

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

161617572 is a wasteful number, since it uses less digits than its factorization.

161617572 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 203 (or 195 counting only the distinct ones).

The product of its digits is 17640, while the sum is 36.

The square root of 161617572 is about 12712.8899940179. The cubic root of 161617572 is about 544.7068782599.

The spelling of 161617572 in words is "one hundred sixty-one million, six hundred seventeen thousand, five hundred seventy-two".