71725921 has 8 divisors (see below), whose sum is σ = 72424040. Its totient is φ = 71031168.

The previous prime is 71725889. The next prime is 71725957. The reversal of 71725921 is 12952717.

It can be written as a sum of positive squares in 4 ways, for example, as 4157521 + 67568400 = 2039^2 + 8220^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 71725921 - 2⁵ = 71725889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71725981) 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, 63655 + ... + 64771.

It is an arithmetic number, because the mean of its divisors is an integer number (9053005).

Almost surely, 2^71725921 is an apocalyptic number.

It is an amenable number.

71725921 is a deficient number, since it is larger than the sum of its proper divisors (698119).

71725921 is a wasteful number, since it uses less digits than its factorization.

71725921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1683.

The product of its digits is 8820, while the sum is 34.

The square root of 71725921 is about 8469.1157153507. The cubic root of 71725921 is about 415.4882162511.

The spelling of 71725921 in words is "seventy-one million, seven hundred twenty-five thousand, nine hundred twenty-one".