21330426432461 has 2 divisors, whose sum is σ = 21330426432462. Its totient is φ = 21330426432460.

The previous prime is 21330426432451. The next prime is 21330426432517. The reversal of 21330426432461 is 16423462403312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16315290129961 + 5015136302500 = 4039219^2 + 2239450^2 .

It is a cyclic number.

It is not a de Polignac number, because 21330426432461 - 2¹⁴ = 21330426416077 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21330426432451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10665213216230 + 10665213216231.

It is an arithmetic number, because the mean of its divisors is an integer number (10665213216231).

Almost surely, 2^{21330426432461} is an apocalyptic number.

It is an amenable number.

21330426432461 is a deficient number, since it is larger than the sum of its proper divisors (1).

21330426432461 is an equidigital number, since it uses as much as digits as its factorization.

21330426432461 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 497664, while the sum is 41.

Adding to 21330426432461 its reverse (16423462403312), we get a palindrome (37753888835773).

The spelling of 21330426432461 in words is "twenty-one trillion, three hundred thirty billion, four hundred twenty-six million, four hundred thirty-two thousand, four hundred sixty-one".