161315800 has 24 divisors (see below), whose sum is σ = 375059700. Its totient is φ = 64526240.

The previous prime is 161315779. The next prime is 161315801. The reversal of 161315800 is 8513161.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161315801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 403090 + ... + 403489.

Almost surely, 2^161315800 is an apocalyptic number.

161315800 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161315800 is an abundant number, since it is smaller than the sum of its proper divisors (213743900).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

161315800 is a wasteful number, since it uses less digits than its factorization.

161315800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 806595 (or 806586 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 25.

The square root of 161315800 is about 12701.0157074149. The cubic root of 161315800 is about 544.3676418419.

Adding to 161315800 its reverse (8513161), we get a palindrome (169828961).

The spelling of 161315800 in words is "one hundred sixty-one million, three hundred fifteen thousand, eight hundred".