161818725 has 24 divisors (see below), whose sum is σ = 281623840. Its totient is φ = 81760320.

The previous prime is 161818717. The next prime is 161818751. The reversal of 161818725 is 527818161.

It is not a de Polignac number, because 161818725 - 2³ = 161818717 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 55354 + ... + 58203.

Almost surely, 2^161818725 is an apocalyptic number.

161818725 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

161818725 is a deficient number, since it is larger than the sum of its proper divisors (119805115).

161818725 is a wasteful number, since it uses less digits than its factorization.

161818725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 113589 (or 113584 counting only the distinct ones).

The product of its digits is 26880, while the sum is 39.

The square root of 161818725 is about 12720.7989135903. The cubic root of 161818725 is about 544.9327695314.

The spelling of 161818725 in words is "one hundred sixty-one million, eight hundred eighteen thousand, seven hundred twenty-five".