212978749 has 4 divisors (see below), whose sum is σ = 213055164. Its totient is φ = 212902336.

The previous prime is 212978713. The next prime is 212978767. The reversal of 212978749 is 947879212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 116251524 + 96727225 = 10782^2 + 9835^2 .

It is a cyclic number.

It is not a de Polignac number, because 212978749 - 2⁹ = 212978237 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212976749) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 33862 + ... + 39655.

It is an arithmetic number, because the mean of its divisors is an integer number (53263791).

Almost surely, 2^212978749 is an apocalyptic number.

It is an amenable number.

212978749 is a deficient number, since it is larger than the sum of its proper divisors (76415).

212978749 is an equidigital number, since it uses as much as digits as its factorization.

212978749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76414.

The product of its digits is 508032, while the sum is 49.

The square root of 212978749 is about 14593.7914539026. The cubic root of 212978749 is about 597.1894001421.

The spelling of 212978749 in words is "two hundred twelve million, nine hundred seventy-eight thousand, seven hundred forty-nine".