21231320200157 has 2 divisors, whose sum is σ = 21231320200158. Its totient is φ = 21231320200156.

The previous prime is 21231320200117. The next prime is 21231320200193. The reversal of 21231320200157 is 75100202313212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19804511451076 + 1426808749081 = 4450226^2 + 1194491^2 .

It is a cyclic number.

It is not a de Polignac number, because 21231320200157 - 2²² = 21231316005853 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21231320200117) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10615660100078 + 10615660100079.

It is an arithmetic number, because the mean of its divisors is an integer number (10615660100079).

Almost surely, 2^{21231320200157} is an apocalyptic number.

It is an amenable number.

21231320200157 is a deficient number, since it is larger than the sum of its proper divisors (1).

21231320200157 is an equidigital number, since it uses as much as digits as its factorization.

21231320200157 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5040, while the sum is 29.

Adding to 21231320200157 its reverse (75100202313212), we get a palindrome (96331522513369).

The spelling of 21231320200157 in words is "twenty-one trillion, two hundred thirty-one billion, three hundred twenty million, two hundred thousand, one hundred fifty-seven".