213811397 has 4 divisors (see below), whose sum is σ = 226388556. Its totient is φ = 201234240.

The previous prime is 213811369. The next prime is 213811399. The reversal of 213811397 is 793118312.

It is a happy number.

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 199628641 + 14182756 = 14129^2 + 3766^2 .

It is a cyclic number.

It is not a de Polignac number, because 213811397 - 2⁶ = 213811333 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213811399) 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 3 ways as a sum of consecutive naturals, for example, 6288554 + ... + 6288587.

It is an arithmetic number, because the mean of its divisors is an integer number (56597139).

Almost surely, 2^213811397 is an apocalyptic number.

It is an amenable number.

213811397 is a deficient number, since it is larger than the sum of its proper divisors (12577159).

213811397 is a wasteful number, since it uses less digits than its factorization.

213811397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12577158.

The product of its digits is 9072, while the sum is 35.

The square root of 213811397 is about 14622.2910995507. The cubic root of 213811397 is about 597.9666325532.

The spelling of 213811397 in words is "two hundred thirteen million, eight hundred eleven thousand, three hundred ninety-seven".