726001781 has 4 divisors (see below), whose sum is σ = 726122412. Its totient is φ = 725881152.

The previous prime is 726001733. The next prime is 726001789. The reversal of 726001781 is 187100627.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 401641681 + 324360100 = 20041^2 + 18010^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-726001781 is a prime.

It is a super-2 number, since 2×726001781² = 1054157172030343922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (726001789) 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, 50786 + ... + 63491.

It is an arithmetic number, because the mean of its divisors is an integer number (181530603).

Almost surely, 2^726001781 is an apocalyptic number.

It is an amenable number.

726001781 is a deficient number, since it is larger than the sum of its proper divisors (120631).

726001781 is a wasteful number, since it uses less digits than its factorization.

726001781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 120630.

The product of its (nonzero) digits is 4704, while the sum is 32.

The square root of 726001781 is about 26944.4202201495. The cubic root of 726001781 is about 898.7644696465.

The spelling of 726001781 in words is "seven hundred twenty-six million, one thousand, seven hundred eighty-one".