21660363154225 has 6 divisors (see below), whose sum is σ = 26858850311270. Its totient is φ = 17328290523360.

The previous prime is 21660363154153. The next prime is 21660363154229. The reversal of 21660363154225 is 52245136306612.

It can be written as a sum of positive squares in 3 ways, for example, as 26171474176 + 21634191680049 = 161776^2 + 4651257^2 .

It is not a de Polignac number, because 21660363154225 - 2⁹ = 21660363153713 is a prime.

It is a super-2 number, since 2×21660363154225² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21660363154229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 433207263060 + ... + 433207263109.

Almost surely, 2^{21660363154225} is an apocalyptic number.

21660363154225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21660363154225 is a deficient number, since it is larger than the sum of its proper divisors (5198487157045).

21660363154225 is an equidigital number, since it uses as much as digits as its factorization.

21660363154225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 866414526179 (or 866414526174 counting only the distinct ones).

The product of its (nonzero) digits is 1555200, while the sum is 46.

The spelling of 21660363154225 in words is "twenty-one trillion, six hundred sixty billion, three hundred sixty-three million, one hundred fifty-four thousand, two hundred twenty-five".