71566921 has 8 divisors (see below), whose sum is σ = 74327264. Its totient is φ = 68856480.

The previous prime is 71566837. The next prime is 71566931. The reversal of 71566921 is 12966517.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-71566921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71566931) 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, 9540 + ... + 15301.

It is an arithmetic number, because the mean of its divisors is an integer number (9290908).

Almost surely, 2^71566921 is an apocalyptic number.

It is an amenable number.

71566921 is a deficient number, since it is larger than the sum of its proper divisors (2760343).

71566921 is a wasteful number, since it uses less digits than its factorization.

71566921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24951.

The product of its digits is 22680, while the sum is 37.

The square root of 71566921 is about 8459.7234588372. The cubic root of 71566921 is about 415.1809749222.

The spelling of 71566921 in words is "seventy-one million, five hundred sixty-six thousand, nine hundred twenty-one".