172206640 has 80 divisors (see below), whose sum is σ = 417384000. Its totient is φ = 65995776.

The previous prime is 172206631. The next prime is 172206647. The reversal of 172206640 is 46602271.

It is a tau number, because it is divible by the number of its divisors (80).

It is a junction number, because it is equal to n+sod(n) for n = 172206599 and 172206608.

It is not an unprimeable number, because it can be changed into a prime (172206647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 461494 + ... + 461866.

It is an arithmetic number, because the mean of its divisors is an integer number (5217300).

Almost surely, 2^172206640 is an apocalyptic number.

172206640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 172206640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (208692000).

172206640 is an abundant number, since it is smaller than the sum of its proper divisors (245177360).

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

172206640 is a wasteful number, since it uses less digits than its factorization.

172206640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 614 (or 608 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 28.

The square root of 172206640 is about 13122.7527599967. The cubic root of 172206640 is about 556.3523980995.

The spelling of 172206640 in words is "one hundred seventy-two million, two hundred six thousand, six hundred forty".