721630153 has 4 divisors (see below), whose sum is σ = 728775108. Its totient is φ = 714485200.

The previous prime is 721630141. The next prime is 721630157. The reversal of 721630153 is 351036127.

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 580424464 + 141205689 = 24092^2 + 11883^2 .

It is a cyclic number.

It is not a de Polignac number, because 721630153 - 2⁹ = 721629641 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (721630157) 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, 3572326 + ... + 3572527.

It is an arithmetic number, because the mean of its divisors is an integer number (182193777).

Almost surely, 2^721630153 is an apocalyptic number.

It is an amenable number.

721630153 is a deficient number, since it is larger than the sum of its proper divisors (7144955).

721630153 is a wasteful number, since it uses less digits than its factorization.

721630153 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7144954.

The product of its (nonzero) digits is 3780, while the sum is 28.

The square root of 721630153 is about 26863.1746634682. The cubic root of 721630153 is about 896.9568631027.

The spelling of 721630153 in words is "seven hundred twenty-one million, six hundred thirty thousand, one hundred fifty-three".