720053921 has 4 divisors (see below), whose sum is σ = 762410052. Its totient is φ = 677697792.

The previous prime is 720053911. The next prime is 720053927. The reversal of 720053921 is 129350027.

720053921 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 313467025 + 406586896 = 17705^2 + 20164^2 .

It is a de Polignac number, because none of the positive numbers 2^k-720053921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (720053927) 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, 21178040 + ... + 21178073.

It is an arithmetic number, because the mean of its divisors is an integer number (190602513).

Almost surely, 2^720053921 is an apocalyptic number.

It is an amenable number.

720053921 is a deficient number, since it is larger than the sum of its proper divisors (42356131).

720053921 is a wasteful number, since it uses less digits than its factorization.

720053921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42356130.

The product of its (nonzero) digits is 3780, while the sum is 29.

The square root of 720053921 is about 26833.8204696983. The cubic root of 720053921 is about 896.3033229960.

The spelling of 720053921 in words is "seven hundred twenty million, fifty-three thousand, nine hundred twenty-one".