21507464232389 has 2 divisors, whose sum is σ = 21507464232390. Its totient is φ = 21507464232388.

The previous prime is 21507464232323. The next prime is 21507464232427. The reversal of 21507464232389 is 98323246470512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11666036451364 + 9841427781025 = 3415558^2 + 3137105^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21507464232389 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21507464238389) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10753732116194 + 10753732116195.

It is an arithmetic number, because the mean of its divisors is an integer number (10753732116195).

It is a 1-persistent number, because it is pandigital, but 2⋅21507464232389 = 43014928464778 is not.

Almost surely, 2^{21507464232389} is an apocalyptic number.

It is an amenable number.

21507464232389 is a deficient number, since it is larger than the sum of its proper divisors (1).

21507464232389 is an equidigital number, since it uses as much as digits as its factorization.

21507464232389 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17418240, while the sum is 56.

The spelling of 21507464232389 in words is "twenty-one trillion, five hundred seven billion, four hundred sixty-four million, two hundred thirty-two thousand, three hundred eighty-nine".