210138977 has 2 divisors, whose sum is σ = 210138978. Its totient is φ = 210138976.

The previous prime is 210138937. The next prime is 210138997. The reversal of 210138977 is 779831012.

210138977 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 115971361 + 94167616 = 10769^2 + 9704^2 .

It is a cyclic number.

It is not a de Polignac number, because 210138977 - 2¹⁸ = 209876833 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 210138977.

It is not a weakly prime, because it can be changed into another prime (210138937) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105069488 + 105069489.

It is an arithmetic number, because the mean of its divisors is an integer number (105069489).

Almost surely, 2^210138977 is an apocalyptic number.

It is an amenable number.

210138977 is a deficient number, since it is larger than the sum of its proper divisors (1).

210138977 is an equidigital number, since it uses as much as digits as its factorization.

210138977 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 21168, while the sum is 38.

The square root of 210138977 is about 14496.1711151600. The cubic root of 210138977 is about 594.5232883364.

Adding to 210138977 its reverse (779831012), we get a palindrome (989969989).

The spelling of 210138977 in words is "two hundred ten million, one hundred thirty-eight thousand, nine hundred seventy-seven".