213873822765 has 40 divisors (see below), whose sum is σ = 384010454520. Its totient is φ = 113881033728.

The previous prime is 213873822727. The next prime is 213873822797. The reversal of 213873822765 is 567228378312.

213873822765 is a `hidden beast` number, since 2 + 1 + 387 + 38 + 227 + 6 + 5 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 8292287844 + 205581534921 = 91062^2 + 453411^2 .

It is not a de Polignac number, because 213873822765 - 2⁷ = 213873822637 is a prime.

It is a super-2 number, since 2×213873822765² (a number of 23 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 178060 + ... + 677829.

It is an arithmetic number, because the mean of its divisors is an integer number (9600261363).

Almost surely, 2^213873822765 is an apocalyptic number.

It is an amenable number.

213873822765 is a deficient number, since it is larger than the sum of its proper divisors (170136631755).

213873822765 is an equidigital number, since it uses as much as digits as its factorization.

213873822765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 856523 (or 856514 counting only the distinct ones).

The product of its digits is 6773760, while the sum is 54.

The spelling of 213873822765 in words is "two hundred thirteen billion, eight hundred seventy-three million, eight hundred twenty-two thousand, seven hundred sixty-five".