21170272051 has 2 divisors, whose sum is σ = 21170272052. Its totient is φ = 21170272050.

The previous prime is 21170271931. The next prime is 21170272063. The reversal of 21170272051 is 15027207112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21170272051 - 2²⁷ = 21036054323 is a prime.

It is not a weakly prime, because it can be changed into another prime (21170272751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10585136025 + 10585136026.

It is an arithmetic number, because the mean of its divisors is an integer number (10585136026).

Almost surely, 2^21170272051 is an apocalyptic number.

21170272051 is a deficient number, since it is larger than the sum of its proper divisors (1).

21170272051 is an equidigital number, since it uses as much as digits as its factorization.

21170272051 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1960, while the sum is 28.

Adding to 21170272051 its reverse (15027207112), we get a palindrome (36197479163).

The spelling of 21170272051 in words is "twenty-one billion, one hundred seventy million, two hundred seventy-two thousand, fifty-one".