72129078 has 72 divisors (see below), whose sum is σ = 185344848. Its totient is φ = 20206368.

The previous prime is 72129077. The next prime is 72129107. The reversal of 72129078 is 87092127.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72129077) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 45975 + ... + 47517.

It is an arithmetic number, because the mean of its divisors is an integer number (2574234).

Almost surely, 2^72129078 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 72129078, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (92672424).

72129078 is an abundant number, since it is smaller than the sum of its proper divisors (113215770).

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

72129078 is a wasteful number, since it uses less digits than its factorization.

72129078 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1618 (or 1608 counting only the distinct ones).

The product of its (nonzero) digits is 14112, while the sum is 36.

The square root of 72129078 is about 8492.8839624712. The cubic root of 72129078 is about 416.2652208811.

It can be divided in two parts, 7212 and 9078, that added together give a triangular number (16290 = T₁₈₀).

The spelling of 72129078 in words is "seventy-two million, one hundred twenty-nine thousand, seventy-eight".