161642520 has 256 divisors, whose sum is σ = 601776000. Its totient is φ = 38320128.

The previous prime is 161642479. The next prime is 161642543. The reversal of 161642520 is 25246161.

161642520 is a `hidden beast` number, since 1 + 616 + 4 + 25 + 20 = 666.

It is a super-2 number, since 2×161642520² = 52256608543900800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

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, 406962 + ... + 407358.

Almost surely, 2^161642520 is an apocalyptic number.

161642520 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 161642520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (300888000).

161642520 is an abundant number, since it is smaller than the sum of its proper divisors (440133480).

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

161642520 is a wasteful number, since it uses less digits than its factorization.

161642520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 459 (or 449 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The square root of 161642520 is about 12713.8711649914. The cubic root of 161642520 is about 544.7349046018.

Adding to 161642520 its reverse (25246161), we get a palindrome (186888681).

The spelling of 161642520 in words is "one hundred sixty-one million, six hundred forty-two thousand, five hundred twenty".