721512216205 has 16 divisors (see below), whose sum is σ = 945344355264. Its totient is φ = 524281006080.

The previous prime is 721512216193. The next prime is 721512216239. The reversal of 721512216205 is 502612215127.

It is not a de Polignac number, because 721512216205 - 2⁷ = 721512216077 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5625399 + ... + 5752228.

It is an arithmetic number, because the mean of its divisors is an integer number (59084022204).

Almost surely, 2^721512216205 is an apocalyptic number.

It is an amenable number.

721512216205 is a deficient number, since it is larger than the sum of its proper divisors (223832139059).

721512216205 is a wasteful number, since it uses less digits than its factorization.

721512216205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11378796.

The product of its (nonzero) digits is 16800, while the sum is 34.

It can be divided in two parts, 7215122 and 16205, that added together give a palindrome (7231327).

The spelling of 721512216205 in words is "seven hundred twenty-one billion, five hundred twelve million, two hundred sixteen thousand, two hundred five".