71397921 has 8 divisors (see below), whose sum is σ = 108796864. Its totient is φ = 40798800.

The previous prime is 71397899. The next prime is 71397959. The reversal of 71397921 is 12979317.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 71397921 - 2⁵ = 71397889 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 71397921.

It is not an unprimeable number, because it can be changed into a prime (71397721) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1699930 + ... + 1699971.

It is an arithmetic number, because the mean of its divisors is an integer number (13599608).

Almost surely, 2^71397921 is an apocalyptic number.

It is an amenable number.

71397921 is a deficient number, since it is larger than the sum of its proper divisors (37398943).

71397921 is a wasteful number, since it uses less digits than its factorization.

71397921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3399911.

The product of its digits is 23814, while the sum is 39.

The square root of 71397921 is about 8449.7290489104. The cubic root of 71397921 is about 414.8539109349.

The spelling of 71397921 in words is "seventy-one million, three hundred ninety-seven thousand, nine hundred twenty-one".