721800043 has 4 divisors (see below), whose sum is σ = 728187768. Its totient is φ = 715412320.

The previous prime is 721800031. The next prime is 721800091. The reversal of 721800043 is 340008127.

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

It is a cyclic number.

It is not a de Polignac number, because 721800043 - 2²⁵ = 688245611 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 721799990 and 721800017.

It is not an unprimeable number, because it can be changed into a prime (721800143) 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, 3193693 + ... + 3193918.

It is an arithmetic number, because the mean of its divisors is an integer number (182046942).

Almost surely, 2^721800043 is an apocalyptic number.

721800043 is a deficient number, since it is larger than the sum of its proper divisors (6387725).

721800043 is a wasteful number, since it uses less digits than its factorization.

721800043 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6387724.

The product of its (nonzero) digits is 1344, while the sum is 25.

The square root of 721800043 is about 26866.3366129437. The cubic root of 721800043 is about 897.0272463612.

The spelling of 721800043 in words is "seven hundred twenty-one million, eight hundred thousand, forty-three".