21340025513 has 2 divisors, whose sum is σ = 21340025514. Its totient is φ = 21340025512.

The previous prime is 21340025477. The next prime is 21340025527. The reversal of 21340025513 is 31552004312.

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., 14265196969 + 7074828544 = 119437^2 + 84112^2 .

It is a cyclic number.

It is not a de Polignac number, because 21340025513 - 2⁶ = 21340025449 is a prime.

It is not a weakly prime, because it can be changed into another prime (21340025533) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10670012756 + 10670012757.

It is an arithmetic number, because the mean of its divisors is an integer number (10670012757).

Almost surely, 2^21340025513 is an apocalyptic number.

It is an amenable number.

21340025513 is a deficient number, since it is larger than the sum of its proper divisors (1).

21340025513 is an equidigital number, since it uses as much as digits as its factorization.

21340025513 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3600, while the sum is 26.

Adding to 21340025513 its reverse (31552004312), we get a palindrome (52892029825).

The spelling of 21340025513 in words is "twenty-one billion, three hundred forty million, twenty-five thousand, five hundred thirteen".