21323404507 has 2 divisors, whose sum is σ = 21323404508. Its totient is φ = 21323404506.

The previous prime is 21323404483. The next prime is 21323404513. The reversal of 21323404507 is 70540432312.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21323404507 is a prime.

It is not a weakly prime, because it can be changed into another prime (21323404567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10661702253 + 10661702254.

It is an arithmetic number, because the mean of its divisors is an integer number (10661702254).

Almost surely, 2^21323404507 is an apocalyptic number.

21323404507 is a deficient number, since it is larger than the sum of its proper divisors (1).

21323404507 is an equidigital number, since it uses as much as digits as its factorization.

21323404507 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 20160, while the sum is 31.

Adding to 21323404507 its reverse (70540432312), we get a palindrome (91863836819).

The spelling of 21323404507 in words is "twenty-one billion, three hundred twenty-three million, four hundred four thousand, five hundred seven".