161638887 has 8 divisors (see below), whose sum is σ = 216034560. Its totient is φ = 107501240.

The previous prime is 161638859. The next prime is 161638891. The reversal of 161638887 is 788836161.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 161638887 - 2⁶ = 161638823 is a prime.

It is a super-2 number, since 2×161638887² = 52254259581197538, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161638847) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 63039 + ... + 65552.

It is an arithmetic number, because the mean of its divisors is an integer number (27004320).

Almost surely, 2^161638887 is an apocalyptic number.

161638887 is a deficient number, since it is larger than the sum of its proper divisors (54395673).

161638887 is a wasteful number, since it uses less digits than its factorization.

161638887 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129013.

The product of its digits is 387072, while the sum is 48.

The square root of 161638887 is about 12713.7282887436. The cubic root of 161638887 is about 544.7308235042.

The spelling of 161638887 in words is "one hundred sixty-one million, six hundred thirty-eight thousand, eight hundred eighty-seven".