213778097 has 8 divisors (see below), whose sum is σ = 234567144. Its totient is φ = 193609728.

The previous prime is 213778093. The next prime is 213778121. The reversal of 213778097 is 790877312.

It can be written as a sum of positive squares in 4 ways, for example, as 38056561 + 175721536 = 6169^2 + 13256^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 213778097 - 2² = 213778093 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (213778093) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 154448 + ... + 155825.

It is an arithmetic number, because the mean of its divisors is an integer number (29320893).

Almost surely, 2^213778097 is an apocalyptic number.

It is an amenable number.

213778097 is a deficient number, since it is larger than the sum of its proper divisors (20789047).

213778097 is a wasteful number, since it uses less digits than its factorization.

213778097 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 310339.

The product of its (nonzero) digits is 148176, while the sum is 44.

The square root of 213778097 is about 14621.1523827638. The cubic root of 213778097 is about 597.9355875559.

The spelling of 213778097 in words is "two hundred thirteen million, seven hundred seventy-eight thousand, ninety-seven".