72121140 has 432 divisors, whose sum is σ = 298024272. Its totient is φ = 13934592.

The previous prime is 72121117. The next prime is 72121183. The reversal of 72121140 is 4112127.

It can be written as a sum of positive squares in 8 ways, for example, as 853776 + 71267364 = 924^2 + 8442^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

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 143 ways as a sum of consecutive naturals, for example, 1949202 + ... + 1949238.

It is an arithmetic number, because the mean of its divisors is an integer number (689871).

Almost surely, 2^72121140 is an apocalyptic number.

72121140 is a gapful number since it is divisible by the number (70) 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 72121140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (149012136).

72121140 is an abundant number, since it is smaller than the sum of its proper divisors (225903132).

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

72121140 is a wasteful number, since it uses less digits than its factorization.

72121140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 96 (or 84 counting only the distinct ones).

The product of its (nonzero) digits is 112, while the sum is 18.

The square root of 72121140 is about 8492.4166171944. The cubic root of 72121140 is about 416.2499499499.

Adding to 72121140 its reverse (4112127), we get a palindrome (76233267).

The spelling of 72121140 in words is "seventy-two million, one hundred twenty-one thousand, one hundred forty".