21660551120325 has 48 divisors (see below), whose sum is σ = 38964485932736. Its totient is φ = 10553721292800.

The previous prime is 21660551120321. The next prime is 21660551120359. The reversal of 21660551120325 is 52302115506612.

It is not a de Polignac number, because 21660551120325 - 2² = 21660551120321 is a prime.

It is a super-2 number, since 2×21660551120325² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21660551120321) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 114420631 + ... + 114609780.

Almost surely, 2^{21660551120325} is an apocalyptic number.

21660551120325 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21660551120325 is a deficient number, since it is larger than the sum of its proper divisors (17303934812411).

21660551120325 is a wasteful number, since it uses less digits than its factorization.

21660551120325 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 229030534 (or 229030529 counting only the distinct ones).

The product of its (nonzero) digits is 108000, while the sum is 39.

Adding to 21660551120325 its reverse (52302115506612), we get a palindrome (73962666626937).

The spelling of 21660551120325 in words is "twenty-one trillion, six hundred sixty billion, five hundred fifty-one million, one hundred twenty thousand, three hundred twenty-five".