66172949 has 2 divisors, whose sum is σ = 66172950. Its totient is φ = 66172948.

The previous prime is 66172937. The next prime is 66172961. The reversal of 66172949 is 94927166.

It is a balanced prime because it is at equal distance from previous prime (66172937) and next prime (66172961).

It can be written as a sum of positive squares in only one way, i.e., 62694724 + 3478225 = 7918^2 + 1865^2 .

It is a cyclic number.

It is not a de Polignac number, because 66172949 - 2⁴ = 66172933 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66172979) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33086474 + 33086475.

It is an arithmetic number, because the mean of its divisors is an integer number (33086475).

Almost surely, 2^66172949 is an apocalyptic number.

It is an amenable number.

66172949 is a deficient number, since it is larger than the sum of its proper divisors (1).

66172949 is an equidigital number, since it uses as much as digits as its factorization.

66172949 is an evil number, because the sum of its binary digits is even.

The product of its digits is 163296, while the sum is 44.

The square root of 66172949 is about 8134.6757157246. The cubic root of 66172949 is about 404.4766883287.

The spelling of 66172949 in words is "sixty-six million, one hundred seventy-two thousand, nine hundred forty-nine".