21313212061 has 2 divisors, whose sum is σ = 21313212062. Its totient is φ = 21313212060.

The previous prime is 21313212049. The next prime is 21313212169. The reversal of 21313212061 is 16021231312.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21288560836 + 24651225 = 145906^2 + 4965^2 .

It is a cyclic number.

It is not a de Polignac number, because 21313212061 - 2¹⁷ = 21313080989 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21313212761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10656606030 + 10656606031.

It is an arithmetic number, because the mean of its divisors is an integer number (10656606031).

Almost surely, 2^21313212061 is an apocalyptic number.

It is an amenable number.

21313212061 is a deficient number, since it is larger than the sum of its proper divisors (1).

21313212061 is an equidigital number, since it uses as much as digits as its factorization.

21313212061 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 432, while the sum is 22.

Adding to 21313212061 its reverse (16021231312), we get a palindrome (37334443373).

The spelling of 21313212061 in words is "twenty-one billion, three hundred thirteen million, two hundred twelve thousand, sixty-one".