72129450 has 48 divisors (see below), whose sum is σ = 181836576. Its totient is φ = 18916800.

The previous prime is 72129439. The next prime is 72129457. The reversal of 72129450 is 5492127.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an alternating number because its digits alternate between odd and even.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (72129457) 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 23 ways as a sum of consecutive naturals, for example, 5209 + ... + 13091.

It is an arithmetic number, because the mean of its divisors is an integer number (3788262).

Almost surely, 2^72129450 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 72129450, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (90918288).

72129450 is an abundant number, since it is smaller than the sum of its proper divisors (109707126).

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

72129450 is a wasteful number, since it uses less digits than its factorization.

72129450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7959 (or 7954 counting only the distinct ones).

The product of its (nonzero) digits is 5040, while the sum is 30.

The square root of 72129450 is about 8492.9058631307. The cubic root of 72129450 is about 416.2659364981.

The spelling of 72129450 in words is "seventy-two million, one hundred twenty-nine thousand, four hundred fifty".