212405157 has 12 divisors (see below), whose sum is σ = 324855180. Its totient is φ = 133273728.

The previous prime is 212405153. The next prime is 212405177. The reversal of 212405157 is 751504212.

It can be written as a sum of positive squares in 2 ways, for example, as 178462881 + 33942276 = 13359^2 + 5826^2 .

It is not a de Polignac number, because 212405157 - 2² = 212405153 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 212405157.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212405153) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 693982 + ... + 694287.

It is an arithmetic number, because the mean of its divisors is an integer number (27071265).

Almost surely, 2^212405157 is an apocalyptic number.

It is an amenable number.

212405157 is a deficient number, since it is larger than the sum of its proper divisors (112450023).

212405157 is a wasteful number, since it uses less digits than its factorization.

212405157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1388292 (or 1388289 counting only the distinct ones).

The product of its (nonzero) digits is 2800, while the sum is 27.

The square root of 212405157 is about 14574.1262859905. The cubic root of 212405157 is about 596.6528035160.

Adding to 212405157 its reverse (751504212), we get a palindrome (963909369).

The spelling of 212405157 in words is "two hundred twelve million, four hundred five thousand, one hundred fifty-seven".