161216625 has 16 divisors (see below), whose sum is σ = 268265088. Its totient is φ = 85982000.

The previous prime is 161216621. The next prime is 161216641. The reversal of 161216625 is 526612161.

It is not a de Polignac number, because 161216625 - 2² = 161216621 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 161216592 and 161216601.

It is not an unprimeable number, because it can be changed into a prime (161216621) 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, 214581 + ... + 215330.

It is an arithmetic number, because the mean of its divisors is an integer number (16766568).

Almost surely, 2^161216625 is an apocalyptic number.

161216625 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

161216625 is a deficient number, since it is larger than the sum of its proper divisors (107048463).

161216625 is an equidigital number, since it uses as much as digits as its factorization.

161216625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 429929 (or 429919 counting only the distinct ones).

The product of its digits is 4320, while the sum is 30.

The square root of 161216625 is about 12697.1108918525. The cubic root of 161216625 is about 544.2560620951.

Adding to 161216625 its reverse (526612161), we get a palindrome (687828786).

The spelling of 161216625 in words is "one hundred sixty-one million, two hundred sixteen thousand, six hundred twenty-five".