71397021 has 16 divisors (see below), whose sum is σ = 97344000. Its totient is φ = 46533168.

The previous prime is 71397017. The next prime is 71397047. The reversal of 71397021 is 12079317.

It is not a de Polignac number, because 71397021 - 2² = 71397017 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 71397021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71397721) 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 in 15 ways as a sum of consecutive naturals, for example, 34210 + ... + 36236.

It is an arithmetic number, because the mean of its divisors is an integer number (6084000).

Almost surely, 2^71397021 is an apocalyptic number.

It is an amenable number.

71397021 is a deficient number, since it is larger than the sum of its proper divisors (25946979).

71397021 is a wasteful number, since it uses less digits than its factorization.

71397021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2288.

The product of its (nonzero) digits is 2646, while the sum is 30.

The square root of 71397021 is about 8449.6757925970. The cubic root of 71397021 is about 414.8521677932.

The spelling of 71397021 in words is "seventy-one million, three hundred ninety-seven thousand, twenty-one".