729162009 has 9 divisors (see below), whose sum is σ = 1053351039. Its totient is φ = 486054000.

The previous prime is 729162001. The next prime is 729162017. The reversal of 729162009 is 900261927.

The square root of 729162009 is 27003.

It is a perfect power (a square), and thus also a powerful number.

729162009 is a `hidden beast` number, since 7 + 29 + 1 + 620 + 0 + 9 = 666.

It is an interprime number because it is at equal distance from previous prime (729162001) and next prime (729162017).

It can be written as a sum of positive squares in only one way, i.e., 129891609 + 599270400 = 11397^2 + 24480^2 .

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 729162009 - 2³ = 729162001 is a prime.

It is not an unprimeable number, because it can be changed into a prime (729162001) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 76509 + ... + 85509.

Almost surely, 2^729162009 is an apocalyptic number.

729162009 is the 27003-rd square number.

729162009 is the 13502-nd centered octagonal number.

It is an amenable number.

729162009 is a deficient number, since it is larger than the sum of its proper divisors (324189030).

729162009 is an frugal number, since it uses more digits than its factorization.

729162009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18008 (or 9004 counting only the distinct ones).

The product of its (nonzero) digits is 13608, while the sum is 36.

The cubic root of 729162009 is about 900.0666654322.

Multiplying 729162009 by its sum of digits (36), we get a square (26249832324 = 162018²).

The spelling of 729162009 in words is "seven hundred twenty-nine million, one hundred sixty-two thousand, nine".