71632721 has 2 divisors, whose sum is σ = 71632722. Its totient is φ = 71632720.

The previous prime is 71632709. The next prime is 71632751. The reversal of 71632721 is 12723617.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 69072721 + 2560000 = 8311^2 + 1600^2 .

It is a cyclic number.

It is not a de Polignac number, because 71632721 - 2¹⁸ = 71370577 is a prime.

It is a Chen prime.

It is equal to p_4208474 and since 71632721 and 4208474 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (71632751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35816360 + 35816361.

It is an arithmetic number, because the mean of its divisors is an integer number (35816361).

Almost surely, 2^71632721 is an apocalyptic number.

It is an amenable number.

71632721 is a deficient number, since it is larger than the sum of its proper divisors (1).

71632721 is an equidigital number, since it uses as much as digits as its factorization.

71632721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3528, while the sum is 29.

The square root of 71632721 is about 8463.6115813523. The cubic root of 71632721 is about 415.3081777301.

The spelling of 71632721 in words is "seventy-one million, six hundred thirty-two thousand, seven hundred twenty-one".