21152154221045 has 16 divisors (see below), whose sum is σ = 25660162380528. Its totient is φ = 16737563650560.

The previous prime is 21152154221017. The next prime is 21152154221059. The reversal of 21152154221045 is 54012245125112.

It can be written as a sum of positive squares in 8 ways, for example, as 126866329489 + 21025287891556 = 356183^2 + 4585334^2 .

It is not a de Polignac number, because 21152154221045 - 2¹⁴ = 21152154204661 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21152154220996 and 21152154221014.

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, 55548626 + ... + 55928115.

It is an arithmetic number, because the mean of its divisors is an integer number (1603760148783).

Almost surely, 2^{21152154221045} is an apocalyptic number.

It is an amenable number.

21152154221045 is a deficient number, since it is larger than the sum of its proper divisors (4508008159483).

21152154221045 is a wasteful number, since it uses less digits than its factorization.

21152154221045 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111477160.

The product of its (nonzero) digits is 32000, while the sum is 35.

Adding to 21152154221045 its reverse (54012245125112), we get a palindrome (75164399346157).

The spelling of 21152154221045 in words is "twenty-one trillion, one hundred fifty-two billion, one hundred fifty-four million, two hundred twenty-one thousand, forty-five".