21545541341431 has 2 divisors, whose sum is σ = 21545541341432. Its totient is φ = 21545541341430.

The previous prime is 21545541341419. The next prime is 21545541341503. The reversal of 21545541341431 is 13414314554512.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21545541341431 is a prime.

It is a super-2 number, since 2×21545541341431² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21545541341131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10772770670715 + 10772770670716.

It is an arithmetic number, because the mean of its divisors is an integer number (10772770670716).

Almost surely, 2^{21545541341431} is an apocalyptic number.

21545541341431 is a deficient number, since it is larger than the sum of its proper divisors (1).

21545541341431 is an equidigital number, since it uses as much as digits as its factorization.

21545541341431 is an evil number, because the sum of its binary digits is even.

The product of its digits is 576000, while the sum is 43.

Adding to 21545541341431 its reverse (13414314554512), we get a palindrome (34959855895943).

The spelling of 21545541341431 in words is "twenty-one trillion, five hundred forty-five billion, five hundred forty-one million, three hundred forty-one thousand, four hundred thirty-one".