72170851 has 2 divisors, whose sum is σ = 72170852. Its totient is φ = 72170850.

The previous prime is 72170843. The next prime is 72170893. The reversal of 72170851 is 15807127.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 72170851 - 2³ = 72170843 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (72170801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36085425 + 36085426.

It is an arithmetic number, because the mean of its divisors is an integer number (36085426).

Almost surely, 2^72170851 is an apocalyptic number.

72170851 is a deficient number, since it is larger than the sum of its proper divisors (1).

72170851 is an equidigital number, since it uses as much as digits as its factorization.

72170851 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3920, while the sum is 31.

The square root of 72170851 is about 8495.3429006721. The cubic root of 72170851 is about 416.3455643052.

Adding to 72170851 its reverse (15807127), we get a palindrome (87977978).

The spelling of 72170851 in words is "seventy-two million, one hundred seventy thousand, eight hundred fifty-one".