721427365 has 4 divisors (see below), whose sum is σ = 865712844. Its totient is φ = 577141888.

The previous prime is 721427363. The next prime is 721427389. The reversal of 721427365 is 563724127.

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 318301281 + 403126084 = 17841^2 + 20078^2 .

It is a cyclic number.

It is not a de Polignac number, because 721427365 - 2¹ = 721427363 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 (721427363) 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, 72142732 + ... + 72142741.

It is an arithmetic number, because the mean of its divisors is an integer number (216428211).

Almost surely, 2^721427365 is an apocalyptic number.

It is an amenable number.

721427365 is a deficient number, since it is larger than the sum of its proper divisors (144285479).

721427365 is a wasteful number, since it uses less digits than its factorization.

721427365 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144285478.

The product of its digits is 70560, while the sum is 37.

The square root of 721427365 is about 26859.3999374521. The cubic root of 721427365 is about 896.8728361589.

It can be divided in two parts, 72142 and 7365, that added together give a cube (79507 = 43³).

The spelling of 721427365 in words is "seven hundred twenty-one million, four hundred twenty-seven thousand, three hundred sixty-five".