21345429493 has 2 divisors, whose sum is σ = 21345429494. Its totient is φ = 21345429492.

The previous prime is 21345429377. The next prime is 21345429541. The reversal of 21345429493 is 39492454312.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18741062404 + 2604367089 = 136898^2 + 51033^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21345429493 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21345459493) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10672714746 + 10672714747.

It is an arithmetic number, because the mean of its divisors is an integer number (10672714747).

Almost surely, 2^21345429493 is an apocalyptic number.

It is an amenable number.

21345429493 is a deficient number, since it is larger than the sum of its proper divisors (1).

21345429493 is an equidigital number, since it uses as much as digits as its factorization.

21345429493 is an evil number, because the sum of its binary digits is even.

The product of its digits is 933120, while the sum is 46.

The spelling of 21345429493 in words is "twenty-one billion, three hundred forty-five million, four hundred twenty-nine thousand, four hundred ninety-three".