71949989 has 2 divisors, whose sum is σ = 71949990. Its totient is φ = 71949988.

The previous prime is 71949973. The next prime is 71950009. The reversal of 71949989 is 98994917.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 71656225 + 293764 = 8465^2 + 542^2 .

It is a cyclic number.

It is not a de Polignac number, because 71949989 - 2⁴ = 71949973 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 (71949949) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35974994 + 35974995.

It is an arithmetic number, because the mean of its divisors is an integer number (35974995).

Almost surely, 2^71949989 is an apocalyptic number.

It is an amenable number.

71949989 is a deficient number, since it is larger than the sum of its proper divisors (1).

71949989 is an equidigital number, since it uses as much as digits as its factorization.

71949989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1469664, while the sum is 56.

The square root of 71949989 is about 8482.3339358929. Note that the first 3 decimals coincide. The cubic root of 71949989 is about 415.9204209372.

The spelling of 71949989 in words is "seventy-one million, nine hundred forty-nine thousand, nine hundred eighty-nine".