721812263 has 4 divisors (see below), whose sum is σ = 728558280. Its totient is φ = 715066248.

The previous prime is 721812251. The next prime is 721812269. The reversal of 721812263 is 362218127.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 362218127 = 2647 ⋅136841.

It is a cyclic number.

It is not a de Polignac number, because 721812263 - 2¹² = 721808167 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721812269) 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, 3372848 + ... + 3373061.

It is an arithmetic number, because the mean of its divisors is an integer number (182139570).

Almost surely, 2^721812263 is an apocalyptic number.

721812263 is a deficient number, since it is larger than the sum of its proper divisors (6746017).

721812263 is a wasteful number, since it uses less digits than its factorization.

721812263 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6746016.

The product of its digits is 8064, while the sum is 32.

The square root of 721812263 is about 26866.5640341299. The cubic root of 721812263 is about 897.0323085254.

The spelling of 721812263 in words is "seven hundred twenty-one million, eight hundred twelve thousand, two hundred sixty-three".