721690538543 has 8 divisors (see below), whose sum is σ = 802276331136. Its totient is φ = 644686336800.

The previous prime is 721690538519. The next prime is 721690538573. The reversal of 721690538543 is 345835096127.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 721690538543 - 2⁸ = 721690538287 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 (721690538573) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 895397288 + ... + 895398093.

It is an arithmetic number, because the mean of its divisors is an integer number (100284541392).

It is a 1-persistent number, because it is pandigital, but 2⋅721690538543 = 1443381077086 is not.

Almost surely, 2^721690538543 is an apocalyptic number.

721690538543 is a deficient number, since it is larger than the sum of its proper divisors (80585792593).

721690538543 is a wasteful number, since it uses less digits than its factorization.

721690538543 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1790795425.

The product of its (nonzero) digits is 5443200, while the sum is 53.

The spelling of 721690538543 in words is "seven hundred twenty-one billion, six hundred ninety million, five hundred thirty-eight thousand, five hundred forty-three".