726741921 has 4 divisors (see below), whose sum is σ = 968989232. Its totient is φ = 484494612.

The previous prime is 726741919. The next prime is 726741979. The reversal of 726741921 is 129147627.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 726741921 - 2¹ = 726741919 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 726741921.

It is not an unprimeable number, because it can be changed into a prime (726741991) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 121123651 + ... + 121123656.

It is an arithmetic number, because the mean of its divisors is an integer number (242247308).

Almost surely, 2^726741921 is an apocalyptic number.

It is an amenable number.

726741921 is a deficient number, since it is larger than the sum of its proper divisors (242247311).

726741921 is a wasteful number, since it uses less digits than its factorization.

726741921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 242247310.

The product of its digits is 42336, while the sum is 39.

The square root of 726741921 is about 26958.1512904724. The cubic root of 726741921 is about 899.0697882763.

The spelling of 726741921 in words is "seven hundred twenty-six million, seven hundred forty-one thousand, nine hundred twenty-one".