721552818 has 16 divisors (see below), whose sum is σ = 1649263680. Its totient is φ = 206157936.

The previous prime is 721552813. The next prime is 721552823. The reversal of 721552818 is 818255127.

It is an interprime number because it is at equal distance from previous prime (721552813) and next prime (721552823).

It is a super-2 number, since 2×721552818² = 1041276938327482248, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (721552813) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8589873 + ... + 8589956.

It is an arithmetic number, because the mean of its divisors is an integer number (103078980).

Almost surely, 2^721552818 is an apocalyptic number.

721552818 is an abundant number, since it is smaller than the sum of its proper divisors (927710862).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

721552818 is a wasteful number, since it uses less digits than its factorization.

721552818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17179841.

The product of its digits is 44800, while the sum is 39.

The square root of 721552818 is about 26861.7352008391. The cubic root of 721552818 is about 896.9248205406.

The spelling of 721552818 in words is "seven hundred twenty-one million, five hundred fifty-two thousand, eight hundred eighteen".