21242321501 has 2 divisors, whose sum is σ = 21242321502. Its totient is φ = 21242321500.

The previous prime is 21242321467. The next prime is 21242321509. The reversal of 21242321501 is 10512324212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14344852900 + 6897468601 = 119770^2 + 83051^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21242321501 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21242321509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10621160750 + 10621160751.

It is an arithmetic number, because the mean of its divisors is an integer number (10621160751).

Almost surely, 2^21242321501 is an apocalyptic number.

It is an amenable number.

21242321501 is a deficient number, since it is larger than the sum of its proper divisors (1).

21242321501 is an equidigital number, since it uses as much as digits as its factorization.

21242321501 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 960, while the sum is 23.

Adding to 21242321501 its reverse (10512324212), we get a palindrome (31754645713).

The spelling of 21242321501 in words is "twenty-one billion, two hundred forty-two million, three hundred twenty-one thousand, five hundred one".