21113010421 has 2 divisors, whose sum is σ = 21113010422. Its totient is φ = 21113010420.

The previous prime is 21113010409. The next prime is 21113010461. The reversal of 21113010421 is 12401031112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17273844900 + 3839165521 = 131430^2 + 61961^2 .

It is a cyclic number.

It is not a de Polignac number, because 21113010421 - 2⁷ = 21113010293 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21113010395 and 21113010404.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21113010461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10556505210 + 10556505211.

It is an arithmetic number, because the mean of its divisors is an integer number (10556505211).

Almost surely, 2^21113010421 is an apocalyptic number.

It is an amenable number.

21113010421 is a deficient number, since it is larger than the sum of its proper divisors (1).

21113010421 is an equidigital number, since it uses as much as digits as its factorization.

21113010421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 48, while the sum is 16.

Adding to 21113010421 its reverse (12401031112), we get a palindrome (33514041533).

The spelling of 21113010421 in words is "twenty-one billion, one hundred thirteen million, ten thousand, four hundred twenty-one".