72129247 has 2 divisors, whose sum is σ = 72129248. Its totient is φ = 72129246.

The previous prime is 72129223. The next prime is 72129259. The reversal of 72129247 is 74292127.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 72129247 - 2¹⁹ = 71604959 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72129217) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36064623 + 36064624.

It is an arithmetic number, because the mean of its divisors is an integer number (36064624).

Almost surely, 2^72129247 is an apocalyptic number.

72129247 is a deficient number, since it is larger than the sum of its proper divisors (1).

72129247 is an equidigital number, since it uses as much as digits as its factorization.

72129247 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 14112, while the sum is 34.

The square root of 72129247 is about 8492.8939119713. The cubic root of 72129247 is about 416.2655459870.

The spelling of 72129247 in words is "seventy-two million, one hundred twenty-nine thousand, two hundred forty-seven".