21255134101 has 2 divisors, whose sum is σ = 21255134102. Its totient is φ = 21255134100.

The previous prime is 21255133981. The next prime is 21255134107. The reversal of 21255134101 is 10143155212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18854036100 + 2401098001 = 137310^2 + 49001^2 .

It is a cyclic number.

It is not a de Polignac number, because 21255134101 - 2¹³ = 21255125909 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21255134107) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10627567050 + 10627567051.

It is an arithmetic number, because the mean of its divisors is an integer number (10627567051).

Almost surely, 2^21255134101 is an apocalyptic number.

It is an amenable number.

21255134101 is a deficient number, since it is larger than the sum of its proper divisors (1).

21255134101 is an equidigital number, since it uses as much as digits as its factorization.

21255134101 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1200, while the sum is 25.

Adding to 21255134101 its reverse (10143155212), we get a palindrome (31398289313).

The spelling of 21255134101 in words is "twenty-one billion, two hundred fifty-five million, one hundred thirty-four thousand, one hundred one".