21211012357 has 2 divisors, whose sum is σ = 21211012358. Its totient is φ = 21211012356.

The previous prime is 21211012301. The next prime is 21211012373. The reversal of 21211012357 is 75321011212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11411794276 + 9799218081 = 106826^2 + 98991^2 .

It is a cyclic number.

It is not a de Polignac number, because 21211012357 - 2¹⁵ = 21210979589 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21211012457) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605506178 + 10605506179.

It is an arithmetic number, because the mean of its divisors is an integer number (10605506179).

Almost surely, 2^21211012357 is an apocalyptic number.

It is an amenable number.

21211012357 is a deficient number, since it is larger than the sum of its proper divisors (1).

21211012357 is an equidigital number, since it uses as much as digits as its factorization.

21211012357 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 840, while the sum is 25.

Adding to 21211012357 its reverse (75321011212), we get a palindrome (96532023569).

The spelling of 21211012357 in words is "twenty-one billion, two hundred eleven million, twelve thousand, three hundred fifty-seven".