21502023133145 has 8 divisors (see below), whose sum is σ = 27320217628104. Its totient is φ = 16189758594304.

The previous prime is 21502023132937. The next prime is 21502023133177. The reversal of 21502023133145 is 54133132020512.

It can be written as a sum of positive squares in 4 ways, for example, as 11939035894681 + 9562987238464 = 3455291^2 + 3092408^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21502023133145 - 2¹² = 21502023129049 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 126482488934 + ... + 126482489103.

It is an arithmetic number, because the mean of its divisors is an integer number (3415027203513).

Almost surely, 2^{21502023133145} is an apocalyptic number.

It is an amenable number.

21502023133145 is a deficient number, since it is larger than the sum of its proper divisors (5818194494959).

21502023133145 is a wasteful number, since it uses less digits than its factorization.

21502023133145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 252964978059.

The product of its (nonzero) digits is 21600, while the sum is 32.

Adding to 21502023133145 its reverse (54133132020512), we get a palindrome (75635155153657).

The spelling of 21502023133145 in words is "twenty-one trillion, five hundred two billion, twenty-three million, one hundred thirty-three thousand, one hundred forty-five".