71049751021 has 2 divisors, whose sum is σ = 71049751022. Its totient is φ = 71049751020.

The previous prime is 71049750997. The next prime is 71049751033. The reversal of 71049751021 is 12015794017.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 68402648521 + 2647102500 = 261539^2 + 51450^2 .

It is a cyclic number.

It is not a de Polignac number, because 71049751021 - 2¹⁵ = 71049718253 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (71049151021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35524875510 + 35524875511.

It is an arithmetic number, because the mean of its divisors is an integer number (35524875511).

Almost surely, 2^71049751021 is an apocalyptic number.

It is an amenable number.

71049751021 is a deficient number, since it is larger than the sum of its proper divisors (1).

71049751021 is an equidigital number, since it uses as much as digits as its factorization.

71049751021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17640, while the sum is 37.

The spelling of 71049751021 in words is "seventy-one billion, forty-nine million, seven hundred fifty-one thousand, twenty-one".