726691109 has 12 divisors (see below), whose sum is σ = 752980452. Its totient is φ = 701126400.

The previous prime is 726691087. The next prime is 726691153. The reversal of 726691109 is 901196627.

It can be written as a sum of positive squares in 6 ways, for example, as 47306884 + 679384225 = 6878^2 + 26065^2 .

It is not a de Polignac number, because 726691109 - 2²⁸ = 458255653 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (726691169) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 169229 + ... + 173469.

It is an arithmetic number, because the mean of its divisors is an integer number (62748371).

Almost surely, 2^726691109 is an apocalyptic number.

It is an amenable number.

726691109 is a deficient number, since it is larger than the sum of its proper divisors (26289343).

726691109 is an equidigital number, since it uses as much as digits as its factorization.

726691109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4408 (or 4355 counting only the distinct ones).

The product of its (nonzero) digits is 40824, while the sum is 41.

The square root of 726691109 is about 26957.2088503242. The cubic root of 726691109 is about 899.0488342084.

The spelling of 726691109 in words is "seven hundred twenty-six million, six hundred ninety-one thousand, one hundred nine".