21202212457 has 2 divisors, whose sum is σ = 21202212458. Its totient is φ = 21202212456.

The previous prime is 21202212397. The next prime is 21202212463. The reversal of 21202212457 is 75421220212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17555985001 + 3646227456 = 132499^2 + 60384^2 .

It is a cyclic number.

It is not a de Polignac number, because 21202212457 - 2¹⁵ = 21202179689 is a prime.

It is a super-3 number, since 3×21202212457³ (a number of 32 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (21202212497) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10601106228 + 10601106229.

It is an arithmetic number, because the mean of its divisors is an integer number (10601106229).

Almost surely, 2^21202212457 is an apocalyptic number.

It is an amenable number.

21202212457 is a deficient number, since it is larger than the sum of its proper divisors (1).

21202212457 is an equidigital number, since it uses as much as digits as its factorization.

21202212457 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4480, while the sum is 28.

Adding to 21202212457 its reverse (75421220212), we get a palindrome (96623432669).

The spelling of 21202212457 in words is "twenty-one billion, two hundred two million, two hundred twelve thousand, four hundred fifty-seven".