172400078 has 4 divisors (see below), whose sum is σ = 258600120. Its totient is φ = 86200038.

The previous prime is 172400071. The next prime is 172400093. The reversal of 172400078 is 870004271.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 870004271 = 461 ⋅1887211.

It is a self number, because there is not a number n which added to its sum of digits gives 172400078.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (172400071) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43100018 + ... + 43100021.

It is an arithmetic number, because the mean of its divisors is an integer number (64650030).

Almost surely, 2^172400078 is an apocalyptic number.

172400078 is a deficient number, since it is larger than the sum of its proper divisors (86200042).

172400078 is an equidigital number, since it uses as much as digits as its factorization.

172400078 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86200041.

The product of its (nonzero) digits is 3136, while the sum is 29.

The square root of 172400078 is about 13130.1210200059. The cubic root of 172400078 is about 556.5606351807.

The spelling of 172400078 in words is "one hundred seventy-two million, four hundred thousand, seventy-eight".