21212000977 has 2 divisors, whose sum is σ = 21212000978. Its totient is φ = 21212000976.

The previous prime is 21212000969. The next prime is 21212000987. The reversal of 21212000977 is 77900021212.

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., 17370976401 + 3841024576 = 131799^2 + 61976^2 .

It is a cyclic number.

It is not a de Polignac number, because 21212000977 - 2³ = 21212000969 is a prime.

It is not a weakly prime, because it can be changed into another prime (21212000987) 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, 10606000488 + 10606000489.

It is an arithmetic number, because the mean of its divisors is an integer number (10606000489).

Almost surely, 2^21212000977 is an apocalyptic number.

It is an amenable number.

21212000977 is a deficient number, since it is larger than the sum of its proper divisors (1).

21212000977 is an equidigital number, since it uses as much as digits as its factorization.

21212000977 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3528, while the sum is 31.

The spelling of 21212000977 in words is "twenty-one billion, two hundred twelve million, nine hundred seventy-seven", and thus it is an aban number.