21043551301 has 2 divisors, whose sum is σ = 21043551302. Its totient is φ = 21043551300.

The previous prime is 21043551233. The next prime is 21043551313. The reversal of 21043551301 is 10315534012.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20750114401 + 293436900 = 144049^2 + 17130^2 .

It is a cyclic number.

It is not a de Polignac number, because 21043551301 - 2¹¹ = 21043549253 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21043551341) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10521775650 + 10521775651.

It is an arithmetic number, because the mean of its divisors is an integer number (10521775651).

Almost surely, 2^21043551301 is an apocalyptic number.

It is an amenable number.

21043551301 is a deficient number, since it is larger than the sum of its proper divisors (1).

21043551301 is an equidigital number, since it uses as much as digits as its factorization.

21043551301 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1800, while the sum is 25.

The spelling of 21043551301 in words is "twenty-one billion, forty-three million, five hundred fifty-one thousand, three hundred one".