21051372193 has 2 divisors, whose sum is σ = 21051372194. Its totient is φ = 21051372192.

The previous prime is 21051372179. The next prime is 21051372233. The reversal of 21051372193 is 39127315012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20291432704 + 759939489 = 142448^2 + 27567^2 .

It is a cyclic number.

It is not a de Polignac number, because 21051372193 - 2⁹ = 21051371681 is a prime.

It is not a weakly prime, because it can be changed into another prime (21051372143) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10525686096 + 10525686097.

It is an arithmetic number, because the mean of its divisors is an integer number (10525686097).

Almost surely, 2^21051372193 is an apocalyptic number.

It is an amenable number.

21051372193 is a deficient number, since it is larger than the sum of its proper divisors (1).

21051372193 is an equidigital number, since it uses as much as digits as its factorization.

21051372193 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11340, while the sum is 34.

The spelling of 21051372193 in words is "twenty-one billion, fifty-one million, three hundred seventy-two thousand, one hundred ninety-three".