71550989 has 2 divisors, whose sum is σ = 71550990. Its totient is φ = 71550988.

The previous prime is 71550961. The next prime is 71551001. The reversal of 71550989 is 98905517.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 71537764 + 13225 = 8458^2 + 115^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-71550989 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (71550949) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35775494 + 35775495.

It is an arithmetic number, because the mean of its divisors is an integer number (35775495).

Almost surely, 2^71550989 is an apocalyptic number.

It is an amenable number.

71550989 is a deficient number, since it is larger than the sum of its proper divisors (1).

71550989 is an equidigital number, since it uses as much as digits as its factorization.

71550989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 113400, while the sum is 44.

The square root of 71550989 is about 8458.7817680798. The cubic root of 71550989 is about 415.1501638803.

The spelling of 71550989 in words is "seventy-one million, five hundred fifty thousand, nine hundred eighty-nine".