21143242031 has 2 divisors, whose sum is σ = 21143242032. Its totient is φ = 21143242030.

The previous prime is 21143241991. The next prime is 21143242049. The reversal of 21143242031 is 13024234112.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21143242031 is a prime.

It is a super-2 number, since 2×21143242031² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21143241988 and 21143242006.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21143245031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10571621015 + 10571621016.

It is an arithmetic number, because the mean of its divisors is an integer number (10571621016).

Almost surely, 2^21143242031 is an apocalyptic number.

21143242031 is a deficient number, since it is larger than the sum of its proper divisors (1).

21143242031 is an equidigital number, since it uses as much as digits as its factorization.

21143242031 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1152, while the sum is 23.

Adding to 21143242031 its reverse (13024234112), we get a palindrome (34167476143).

The spelling of 21143242031 in words is "twenty-one billion, one hundred forty-three million, two hundred forty-two thousand, thirty-one".