721953601 has 4 divisors (see below), whose sum is σ = 753342912. Its totient is φ = 690564292.

The previous prime is 721953599. The next prime is 721953607. The reversal of 721953601 is 106359127.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 721953601 - 2¹ = 721953599 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (721953607) 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, 15694621 + ... + 15694666.

It is an arithmetic number, because the mean of its divisors is an integer number (188335728).

Almost surely, 2^721953601 is an apocalyptic number.

It is an amenable number.

721953601 is a deficient number, since it is larger than the sum of its proper divisors (31389311).

721953601 is a wasteful number, since it uses less digits than its factorization.

721953601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31389310.

The product of its (nonzero) digits is 11340, while the sum is 34.

The square root of 721953601 is about 26869.1942752290. The cubic root of 721953601 is about 897.0908539786.

The spelling of 721953601 in words is "seven hundred twenty-one million, nine hundred fifty-three thousand, six hundred one".