21113433401 has 2 divisors, whose sum is σ = 21113433402. Its totient is φ = 21113433400.

The previous prime is 21113433391. The next prime is 21113433409. The reversal of 21113433401 is 10433431112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18982226176 + 2131207225 = 137776^2 + 46165^2 .

It is a cyclic number.

It is not a de Polignac number, because 21113433401 - 2¹⁸ = 21113171257 is a prime.

It is not a weakly prime, because it can be changed into another prime (21113433409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10556716700 + 10556716701.

It is an arithmetic number, because the mean of its divisors is an integer number (10556716701).

Almost surely, 2^21113433401 is an apocalyptic number.

It is an amenable number.

21113433401 is a deficient number, since it is larger than the sum of its proper divisors (1).

21113433401 is an equidigital number, since it uses as much as digits as its factorization.

21113433401 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 864, while the sum is 23.

Adding to 21113433401 its reverse (10433431112), we get a palindrome (31546864513).

The spelling of 21113433401 in words is "twenty-one billion, one hundred thirteen million, four hundred thirty-three thousand, four hundred one".