71997949 has 2 divisors, whose sum is σ = 71997950. Its totient is φ = 71997948.

The previous prime is 71997931. The next prime is 71997971. The reversal of 71997949 is 94979917.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 71740900 + 257049 = 8470^2 + 507^2 .

It is a cyclic number.

It is not a de Polignac number, because 71997949 - 2¹⁵ = 71965181 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 71997949.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (71997979) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35998974 + 35998975.

It is an arithmetic number, because the mean of its divisors is an integer number (35998975).

Almost surely, 2^71997949 is an apocalyptic number.

It is an amenable number.

71997949 is a deficient number, since it is larger than the sum of its proper divisors (1).

71997949 is an equidigital number, since it uses as much as digits as its factorization.

71997949 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1285956, while the sum is 55.

The square root of 71997949 is about 8485.1605170439. The cubic root of 71997949 is about 416.0128143396.

The spelling of 71997949 in words is "seventy-one million, nine hundred ninety-seven thousand, nine hundred forty-nine".