721620541337 has 4 divisors (see below), whose sum is σ = 721674775140. Its totient is φ = 721566307536.

The previous prime is 721620541331. The next prime is 721620541339. The reversal of 721620541337 is 733145026127.

It is a happy number.

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 383729452681 + 337891088656 = 619459^2 + 581284^2 .

It is a cyclic number.

It is not a de Polignac number, because 721620541337 - 2²⁴ = 721603764121 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 721620541294 and 721620541303.

It is not an unprimeable number, because it can be changed into a prime (721620541331) 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, 27096938 + ... + 27123555.

It is an arithmetic number, because the mean of its divisors is an integer number (180418693785).

Almost surely, 2^721620541337 is an apocalyptic number.

It is an amenable number.

721620541337 is a deficient number, since it is larger than the sum of its proper divisors (54233803).

721620541337 is a wasteful number, since it uses less digits than its factorization.

721620541337 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54233802.

The product of its (nonzero) digits is 211680, while the sum is 41.

The spelling of 721620541337 in words is "seven hundred twenty-one billion, six hundred twenty million, five hundred forty-one thousand, three hundred thirty-seven".