72400109 has 2 divisors, whose sum is σ = 72400110. Its totient is φ = 72400108.

The previous prime is 72400099. The next prime is 72400147. The reversal of 72400109 is 90100427.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 64048009 + 8352100 = 8003^2 + 2890^2 .

It is a cyclic number.

It is not a de Polignac number, because 72400109 - 2¹⁶ = 72334573 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72400709) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36200054 + 36200055.

It is an arithmetic number, because the mean of its divisors is an integer number (36200055).

Almost surely, 2^72400109 is an apocalyptic number.

It is an amenable number.

72400109 is a deficient number, since it is larger than the sum of its proper divisors (1).

72400109 is an equidigital number, since it uses as much as digits as its factorization.

72400109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 504, while the sum is 23.

The square root of 72400109 is about 8508.8253595899. The cubic root of 72400109 is about 416.7859529044.

The spelling of 72400109 in words is "seventy-two million, four hundred thousand, one hundred nine".