71783021 has 2 divisors, whose sum is σ = 71783022. Its totient is φ = 71783020.

The previous prime is 71782981. The next prime is 71783029. The reversal of 71783021 is 12038717.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 45630025 + 26152996 = 6755^2 + 5114^2 .

It is an emirp because it is prime and its reverse (12038717) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 71783021 - 2¹⁴ = 71766637 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (71783029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35891510 + 35891511.

It is an arithmetic number, because the mean of its divisors is an integer number (35891511).

Almost surely, 2^71783021 is an apocalyptic number.

It is an amenable number.

71783021 is a deficient number, since it is larger than the sum of its proper divisors (1).

71783021 is an equidigital number, since it uses as much as digits as its factorization.

71783021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2352, while the sum is 29.

The square root of 71783021 is about 8472.4861168373. The cubic root of 71783021 is about 415.5984417876.

It can be divided in two parts, 717 and 83021, that added together give a palindrome (83738).

The spelling of 71783021 in words is "seventy-one million, seven hundred eighty-three thousand, twenty-one".