21369525286221 has 24 divisors (see below), whose sum is σ = 35276819597760. Its totient is φ = 12211107829056.

The previous prime is 21369525286217. The next prime is 21369525286231. The reversal of 21369525286221 is 12268252596312.

21369525286221 is a `hidden beast` number, since 2 + 1 + 3 + 6 + 9 + 5 + 2 + 5 + 2 + 8 + 622 + 1 = 666.

It is not a de Polignac number, because 21369525286221 - 2² = 21369525286217 is a prime.

It is a super-2 number, since 2×21369525286221² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21369525286201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 19788961 + ... + 20840873.

It is an arithmetic number, because the mean of its divisors is an integer number (1469867483240).

Almost surely, 2^{21369525286221} is an apocalyptic number.

21369525286221 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21369525286221 is a deficient number, since it is larger than the sum of its proper divisors (13907294311539).

21369525286221 is a wasteful number, since it uses less digits than its factorization.

21369525286221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1374385 (or 1374382 counting only the distinct ones).

The product of its digits is 6220800, while the sum is 54.

The spelling of 21369525286221 in words is "twenty-one trillion, three hundred sixty-nine billion, five hundred twenty-five million, two hundred eighty-six thousand, two hundred twenty-one".