71721793 has 32 divisors (see below), whose sum is σ = 90260352. Its totient is φ = 55987200.

The previous prime is 71721791. The next prime is 71721823. The reversal of 71721793 is 39712717.

It is a cyclic number.

It is not a de Polignac number, because 71721793 - 2¹ = 71721791 is a prime.

It is a super-2 number, since 2×71721793² = 10288031182269698, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (71721791) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 396163 + ... + 396343.

It is an arithmetic number, because the mean of its divisors is an integer number (2820636).

Almost surely, 2^71721793 is an apocalyptic number.

It is an amenable number.

71721793 is a deficient number, since it is larger than the sum of its proper divisors (18538559).

71721793 is a wasteful number, since it uses less digits than its factorization.

71721793 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 385.

The product of its digits is 18522, while the sum is 37.

The square root of 71721793 is about 8468.8720028112. The cubic root of 71721793 is about 415.4802453147.

It can be divided in two parts, 7172 and 1793, that multiplied together give a square (12859396 = 3586²).

The spelling of 71721793 in words is "seventy-one million, seven hundred twenty-one thousand, seven hundred ninety-three".