71633721 has 4 divisors (see below), whose sum is σ = 95511632. Its totient is φ = 47755812.

The previous prime is 71633713. The next prime is 71633747. The reversal of 71633721 is 12733617.

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 not a de Polignac number, because 71633721 - 2³ = 71633713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71632721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11938951 + ... + 11938956.

It is an arithmetic number, because the mean of its divisors is an integer number (23877908).

Almost surely, 2^71633721 is an apocalyptic number.

It is an amenable number.

71633721 is a deficient number, since it is larger than the sum of its proper divisors (23877911).

71633721 is a wasteful number, since it uses less digits than its factorization.

71633721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23877910.

The product of its digits is 5292, while the sum is 30.

The square root of 71633721 is about 8463.6706575811. The cubic root of 71633721 is about 415.3101103025.

The spelling of 71633721 in words is "seventy-one million, six hundred thirty-three thousand, seven hundred twenty-one".