71021513 has 4 divisors (see below), whose sum is σ = 72021888. Its totient is φ = 70021140.

The previous prime is 71021497. The next prime is 71021521. The reversal of 71021513 is 31512017.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 71021513 - 2⁴ = 71021497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71021213) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 500081 + ... + 500222.

It is an arithmetic number, because the mean of its divisors is an integer number (18005472).

Almost surely, 2^71021513 is an apocalyptic number.

It is an amenable number.

71021513 is a deficient number, since it is larger than the sum of its proper divisors (1000375).

71021513 is a wasteful number, since it uses less digits than its factorization.

71021513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1000374.

The product of its (nonzero) digits is 210, while the sum is 20.

The square root of 71021513 is about 8427.4262381821. The cubic root of 71021513 is about 414.1235929782.

The spelling of 71021513 in words is "seventy-one million, twenty-one thousand, five hundred thirteen".