172478881 has 4 divisors (see below), whose sum is σ = 172538500. Its totient is φ = 172419264.

The previous prime is 172478869. The next prime is 172478899. The reversal of 172478881 is 188874271.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 100500625 + 71978256 = 10025^2 + 8484^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-172478881 is a prime.

It is a super-2 number, since 2×172478881² = 59497928782024322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (172478281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25236 + ... + 31333.

It is an arithmetic number, because the mean of its divisors is an integer number (43134625).

Almost surely, 2^172478881 is an apocalyptic number.

It is an amenable number.

172478881 is a deficient number, since it is larger than the sum of its proper divisors (59619).

172478881 is an equidigital number, since it uses as much as digits as its factorization.

172478881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59618.

The product of its digits is 200704, while the sum is 46.

The square root of 172478881 is about 13133.1215253648. The cubic root of 172478881 is about 556.6454223947.

The spelling of 172478881 in words is "one hundred seventy-two million, four hundred seventy-eight thousand, eight hundred eighty-one".