213245641817 has 4 divisors (see below), whose sum is σ = 229649152740. Its totient is φ = 196842130896.

The previous prime is 213245641813. The next prime is 213245641823. The reversal of 213245641817 is 718146542312.

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 126326219776 + 86919422041 = 355424^2 + 294821^2 .

It is a cyclic number.

It is not a de Polignac number, because 213245641817 - 2² = 213245641813 is a prime.

It is a super-2 number, since 2×213245641817² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (213245641813) 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, 8201755442 + ... + 8201755467.

It is an arithmetic number, because the mean of its divisors is an integer number (57412288185).

Almost surely, 2^213245641817 is an apocalyptic number.

It is an amenable number.

213245641817 is a deficient number, since it is larger than the sum of its proper divisors (16403510923).

213245641817 is a wasteful number, since it uses less digits than its factorization.

213245641817 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16403510922.

The product of its digits is 322560, while the sum is 44.

The spelling of 213245641817 in words is "two hundred thirteen billion, two hundred forty-five million, six hundred forty-one thousand, eight hundred seventeen".