161620516 has 12 divisors (see below), whose sum is σ = 284302732. Its totient is φ = 80391168.

The previous prime is 161620507. The next prime is 161620519. The reversal of 161620516 is 615026161.

It can be written as a sum of positive squares in 2 ways, for example, as 89302500 + 72318016 = 9450^2 + 8504^2 .

It is a super-2 number, since 2×161620516² = 52242382384212512, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (161620519) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 103905 + ... + 105448.

Almost surely, 2^161620516 is an apocalyptic number.

It is an amenable number.

161620516 is a deficient number, since it is larger than the sum of its proper divisors (122682216).

161620516 is a wasteful number, since it uses less digits than its factorization.

161620516 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 209550 (or 209548 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 28.

The square root of 161620516 is about 12713.0057814822. The cubic root of 161620516 is about 544.7101856711.

Adding to 161620516 its reverse (615026161), we get a palindrome (776646677).

The spelling of 161620516 in words is "one hundred sixty-one million, six hundred twenty thousand, five hundred sixteen".