71985149 has 2 divisors, whose sum is σ = 71985150. Its totient is φ = 71985148.

The previous prime is 71985113. The next prime is 71985161. The reversal of 71985149 is 94158917.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 66945124 + 5040025 = 8182^2 + 2245^2 .

It is an emirp because it is prime and its reverse (94158917) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 71985149 - 2¹⁶ = 71919613 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 (71985169) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35992574 + 35992575.

It is an arithmetic number, because the mean of its divisors is an integer number (35992575).

Almost surely, 2^71985149 is an apocalyptic number.

It is an amenable number.

71985149 is a deficient number, since it is larger than the sum of its proper divisors (1).

71985149 is an equidigital number, since it uses as much as digits as its factorization.

71985149 is an evil number, because the sum of its binary digits is even.

The product of its digits is 90720, while the sum is 44.

The square root of 71985149 is about 8484.4062255411. The cubic root of 71985149 is about 415.9881595650.

The spelling of 71985149 in words is "seventy-one million, nine hundred eighty-five thousand, one hundred forty-nine".