161925515 has 4 divisors (see below), whose sum is σ = 194310624. Its totient is φ = 129540408.

The previous prime is 161925509. The next prime is 161925541. The reversal of 161925515 is 515529161.

161925515 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 515529161 = 7 ⋅73647023.

It is a cyclic number.

It is not a de Polignac number, because 161925515 - 2⁴ = 161925499 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16192547 + ... + 16192556.

It is an arithmetic number, because the mean of its divisors is an integer number (48577656).

Almost surely, 2^161925515 is an apocalyptic number.

161925515 is a deficient number, since it is larger than the sum of its proper divisors (32385109).

161925515 is an equidigital number, since it uses as much as digits as its factorization.

161925515 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32385108.

The product of its digits is 13500, while the sum is 35.

The square root of 161925515 is about 12724.9956777989. The cubic root of 161925515 is about 545.0526167532.

The spelling of 161925515 in words is "one hundred sixty-one million, nine hundred twenty-five thousand, five hundred fifteen".