172420420 has 48 divisors (see below), whose sum is σ = 384289920. Its totient is φ = 64841216.

The previous prime is 172420337. The next prime is 172420427. The reversal of 172420420 is 24024271.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 172420391 and 172420400.

It is not an unprimeable number, because it can be changed into a prime (172420427) 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 15 ways as a sum of consecutive naturals, for example, 23964 + ... + 30316.

It is an arithmetic number, because the mean of its divisors is an integer number (8006040).

Almost surely, 2^172420420 is an apocalyptic number.

172420420 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 172420420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (192144960).

172420420 is an abundant number, since it is smaller than the sum of its proper divisors (211869500).

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

172420420 is a wasteful number, since it uses less digits than its factorization.

172420420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6444 (or 6442 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 22.

The square root of 172420420 is about 13130.8956282502. The cubic root of 172420420 is about 556.5825244036.

Adding to 172420420 its reverse (24024271), we get a palindrome (196444691).

The spelling of 172420420 in words is "one hundred seventy-two million, four hundred twenty thousand, four hundred twenty".