161620005 has 16 divisors (see below), whose sum is σ = 259320960. Its totient is φ = 85954368.

The previous prime is 161620001. The next prime is 161620009. The reversal of 161620005 is 500026161.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (161620001) and next prime (161620009).

It is not a de Polignac number, because 161620005 - 2² = 161620001 is a prime.

It is a super-2 number, since 2×161620005² = 52242052032400050, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161620001) 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, 9622 + ... + 20391.

It is an arithmetic number, because the mean of its divisors is an integer number (16207560).

Almost surely, 2^161620005 is an apocalyptic number.

161620005 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

161620005 is a deficient number, since it is larger than the sum of its proper divisors (97700955).

161620005 is a wasteful number, since it uses less digits than its factorization.

161620005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30380.

The product of its (nonzero) digits is 360, while the sum is 21.

The square root of 161620005 is about 12712.9856839375. The cubic root of 161620005 is about 544.7096115955.

Adding to 161620005 its reverse (500026161), we get a palindrome (661646166).

The spelling of 161620005 in words is "one hundred sixty-one million, six hundred twenty thousand, five".