729215881 has 2 divisors, whose sum is σ = 729215882. Its totient is φ = 729215880.

The previous prime is 729215843. The next prime is 729215909. The reversal of 729215881 is 188512927.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 368025856 + 361190025 = 19184^2 + 19005^2 .

It is a cyclic number.

It is not a de Polignac number, because 729215881 - 2¹⁷ = 729084809 is a prime.

It is a super-2 number, since 2×729215881² = 1063511602205212322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (729215281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 364607940 + 364607941.

It is an arithmetic number, because the mean of its divisors is an integer number (364607941).

Almost surely, 2^729215881 is an apocalyptic number.

It is an amenable number.

729215881 is a deficient number, since it is larger than the sum of its proper divisors (1).

729215881 is an equidigital number, since it uses as much as digits as its factorization.

729215881 is an evil number, because the sum of its binary digits is even.

The product of its digits is 80640, while the sum is 43.

The square root of 729215881 is about 27003.9975003702. The cubic root of 729215881 is about 900.0888311497.

The spelling of 729215881 in words is "seven hundred twenty-nine million, two hundred fifteen thousand, eight hundred eighty-one".