721820266 has 16 divisors (see below), whose sum is σ = 1143901440. Its totient is φ = 341049520.

The previous prime is 721820263. The next prime is 721820269. The reversal of 721820266 is 662028127.

It is an interprime number because it is at equal distance from previous prime (721820263) and next prime (721820269).

It is not an unprimeable number, because it can be changed into a prime (721820263) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 129670 + ... + 135121.

It is an arithmetic number, because the mean of its divisors is an integer number (71493840).

Almost surely, 2^721820266 is an apocalyptic number.

721820266 is a deficient number, since it is larger than the sum of its proper divisors (422081174).

721820266 is a wasteful number, since it uses less digits than its factorization.

721820266 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 264869.

The product of its (nonzero) digits is 16128, while the sum is 34.

The square root of 721820266 is about 26866.7129734919. The cubic root of 721820266 is about 897.0356237564.

The spelling of 721820266 in words is "seven hundred twenty-one million, eight hundred twenty thousand, two hundred sixty-six".