212154220477 has 2 divisors, whose sum is σ = 212154220478. Its totient is φ = 212154220476.

The previous prime is 212154220441. The next prime is 212154220507. The reversal of 212154220477 is 774022451212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 211433512761 + 720707716 = 459819^2 + 26846^2 .

It is a cyclic number.

It is not a de Polignac number, because 212154220477 - 2⁷ = 212154220349 is a prime.

It is a super-2 number, since 2×212154220477² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (212154220427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106077110238 + 106077110239.

It is an arithmetic number, because the mean of its divisors is an integer number (106077110239).

Almost surely, 2^212154220477 is an apocalyptic number.

It is an amenable number.

212154220477 is a deficient number, since it is larger than the sum of its proper divisors (1).

212154220477 is an equidigital number, since it uses as much as digits as its factorization.

212154220477 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 62720, while the sum is 37.

Adding to 212154220477 its reverse (774022451212), we get a palindrome (986176671689).

The spelling of 212154220477 in words is "two hundred twelve billion, one hundred fifty-four million, two hundred twenty thousand, four hundred seventy-seven".