721248887 has 4 divisors (see below), whose sum is σ = 736594656. Its totient is φ = 705903120.

The previous prime is 721248859. The next prime is 721248893. The reversal of 721248887 is 788842127.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 788842127 = 1747 ⋅451541.

It is a cyclic number.

It is not a de Polignac number, because 721248887 - 2⁶ = 721248823 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (47), and also a Moran number because the ratio is a prime number: 15345721 = 721248887 / (7 + 2 + 1 + 2 + 4 + 8 + 8 + 8 + 7).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721248487) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7672814 + ... + 7672907.

It is an arithmetic number, because the mean of its divisors is an integer number (184148664).

Almost surely, 2^721248887 is an apocalyptic number.

721248887 is a deficient number, since it is larger than the sum of its proper divisors (15345769).

721248887 is a wasteful number, since it uses less digits than its factorization.

721248887 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15345768.

The product of its digits is 401408, while the sum is 47.

The square root of 721248887 is about 26856.0772824327. The cubic root of 721248887 is about 896.7988692427.

The spelling of 721248887 in words is "seven hundred twenty-one million, two hundred forty-eight thousand, eight hundred eighty-seven".