212756481 has 18 divisors (see below), whose sum is σ = 357489522. Its totient is φ = 121574880.

The previous prime is 212756459. The next prime is 212756519. The reversal of 212756481 is 184657212.

212756481 is a `hidden beast` number, since 2 + 1 + 2 + 7 + 5 + 648 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 140778225 + 71978256 = 11865^2 + 8484^2 .

It is not a de Polignac number, because 212756481 - 2⁵ = 212756449 is a prime.

It is a super-2 number, since 2×212756481² = 90530640415006722, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (212756381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 240780 + ... + 241661.

It is an arithmetic number, because the mean of its divisors is an integer number (19860529).

Almost surely, 2^212756481 is an apocalyptic number.

212756481 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

212756481 is a deficient number, since it is larger than the sum of its proper divisors (144733041).

212756481 is a wasteful number, since it uses less digits than its factorization.

212756481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 482461 (or 482451 counting only the distinct ones).

The product of its digits is 26880, while the sum is 36.

The square root of 212756481 is about 14586.1743099416. The cubic root of 212756481 is about 596.9815823885.

The spelling of 212756481 in words is "two hundred twelve million, seven hundred fifty-six thousand, four hundred eighty-one".