11721310225 has 27 divisors (see below), whose sum is σ = 14825341947. Its totient is φ = 9192997680.

The previous prime is 11721310207. The next prime is 11721310259. The reversal of 11721310225 is 52201312711.

The square root of 11721310225 is 108265.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 4219671681 + 7501638544 = 64959^2 + 86612^2 .

It is not a de Polignac number, because 11721310225 - 2¹¹ = 11721308177 is a prime.

It is a super-2 number, since 2×11721310225² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 11721310225.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 31937992 + ... + 31938358.

Almost surely, 2^11721310225 is an apocalyptic number.

11721310225 is the 108265-th square number.

11721310225 is the 54133-rd centered octagonal number.

It is an amenable number.

11721310225 is a deficient number, since it is larger than the sum of its proper divisors (3104031722).

11721310225 is an frugal number, since it uses more digits than its factorization.

11721310225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 862 (or 431 counting only the distinct ones).

The product of its (nonzero) digits is 840, while the sum is 25.

Multiplying 11721310225 by its sum of digits (25), we get a square (293032755625 = 541325²).

11721310225 divided by its sum of digits (25) gives a square (468852409 = 21653²).

Adding to 11721310225 its reverse (52201312711), we get a palindrome (63922622936).

The spelling of 11721310225 in words is "eleven billion, seven hundred twenty-one million, three hundred ten thousand, two hundred twenty-five".