72506251 has 2 divisors, whose sum is σ = 72506252. Its totient is φ = 72506250.

The previous prime is 72506243. The next prime is 72506257. The reversal of 72506251 is 15260527.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 72506251 - 2³ = 72506243 is a prime.

It is not a weakly prime, because it can be changed into another prime (72506257) 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 as a sum of consecutive naturals, namely, 36253125 + 36253126.

It is an arithmetic number, because the mean of its divisors is an integer number (36253126).

Almost surely, 2^72506251 is an apocalyptic number.

72506251 is a deficient number, since it is larger than the sum of its proper divisors (1).

72506251 is an equidigital number, since it uses as much as digits as its factorization.

72506251 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4200, while the sum is 28.

The square root of 72506251 is about 8515.0602464105. The cubic root of 72506251 is about 416.9895294562.

Adding to 72506251 its reverse (15260527), we get a palindrome (87766778).

The spelling of 72506251 in words is "seventy-two million, five hundred six thousand, two hundred fifty-one".