721172051 has 4 divisors (see below), whose sum is σ = 721624104. Its totient is φ = 720720000.

The previous prime is 721172033. The next prime is 721172057. The reversal of 721172051 is 150271127.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 721172051 - 2¹⁰ = 721171027 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 721172051.

It is not an unprimeable number, because it can be changed into a prime (721172057) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 223625 + ... + 226826.

It is an arithmetic number, because the mean of its divisors is an integer number (180406026).

Almost surely, 2^721172051 is an apocalyptic number.

721172051 is a deficient number, since it is larger than the sum of its proper divisors (452053).

721172051 is a wasteful number, since it uses less digits than its factorization.

721172051 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 452052.

The product of its (nonzero) digits is 980, while the sum is 26.

The square root of 721172051 is about 26854.6467301285. The cubic root of 721172051 is about 896.7670222219.

The spelling of 721172051 in words is "seven hundred twenty-one million, one hundred seventy-two thousand, fifty-one".