21113202503501 has 2 divisors, whose sum is σ = 21113202503502. Its totient is φ = 21113202503500.

The previous prime is 21113202503423. The next prime is 21113202503551. The reversal of 21113202503501 is 10530520231112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21087841622500 + 25360881001 = 4592150^2 + 159251^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21113202503501 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21113202503551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10556601251750 + 10556601251751.

It is an arithmetic number, because the mean of its divisors is an integer number (10556601251751).

Almost surely, 2^{21113202503501} is an apocalyptic number.

It is an amenable number.

21113202503501 is a deficient number, since it is larger than the sum of its proper divisors (1).

21113202503501 is an equidigital number, since it uses as much as digits as its factorization.

21113202503501 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1800, while the sum is 26.

Adding to 21113202503501 its reverse (10530520231112), we get a palindrome (31643722734613).

The spelling of 21113202503501 in words is "twenty-one trillion, one hundred thirteen billion, two hundred two million, five hundred three thousand, five hundred one".