21203145153503 has 8 divisors (see below), whose sum is σ = 22450599813888. Its totient is φ = 19955713918464.

The previous prime is 21203145153433. The next prime is 21203145153583. The reversal of 21203145153503 is 30535154130212.

It is a happy number.

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 21203145153503 - 2¹⁰ = 21203145152479 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21203145153583) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3975551 + ... + 7629632.

It is an arithmetic number, because the mean of its divisors is an integer number (2806324976736).

Almost surely, 2^{21203145153503} is an apocalyptic number.

21203145153503 is a deficient number, since it is larger than the sum of its proper divisors (1247454660385).

21203145153503 is a wasteful number, since it uses less digits than its factorization.

21203145153503 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11712673.

The product of its (nonzero) digits is 54000, while the sum is 35.

Adding to 21203145153503 its reverse (30535154130212), we get a palindrome (51738299283715).

The spelling of 21203145153503 in words is "twenty-one trillion, two hundred three billion, one hundred forty-five million, one hundred fifty-three thousand, five hundred three".