21042451055623 has 2 divisors, whose sum is σ = 21042451055624. Its totient is φ = 21042451055622.

The previous prime is 21042451055513. The next prime is 21042451055653. The reversal of 21042451055623 is 32655015424012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21042451055623 - 2⁹ = 21042451055111 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21042451055653) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10521225527811 + 10521225527812.

It is an arithmetic number, because the mean of its divisors is an integer number (10521225527812).

Almost surely, 2^{21042451055623} is an apocalyptic number.

21042451055623 is a deficient number, since it is larger than the sum of its proper divisors (1).

21042451055623 is an equidigital number, since it uses as much as digits as its factorization.

21042451055623 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288000, while the sum is 40.

Adding to 21042451055623 its reverse (32655015424012), we get a palindrome (53697466479635).

The spelling of 21042451055623 in words is "twenty-one trillion, forty-two billion, four hundred fifty-one million, fifty-five thousand, six hundred twenty-three".