213078505 has 4 divisors (see below), whose sum is σ = 255694212. Its totient is φ = 170462800.

The previous prime is 213078499. The next prime is 213078511. The reversal of 213078505 is 505870312.

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

It is an interprime number because it is at equal distance from previous prime (213078499) and next prime (213078511).

It can be written as a sum of positive squares in 2 ways, for example, as 142468096 + 70610409 = 11936^2 + 8403^2 .

It is not a de Polignac number, because 213078505 - 2¹⁷ = 212947433 is a prime.

It is a Smith number, since the sum of its digits (31) 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 an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21307846 + ... + 21307855.

It is an arithmetic number, because the mean of its divisors is an integer number (63923553).

Almost surely, 2^213078505 is an apocalyptic number.

It is an amenable number.

213078505 is a deficient number, since it is larger than the sum of its proper divisors (42615707).

213078505 is an equidigital number, since it uses as much as digits as its factorization.

213078505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42615706.

The product of its (nonzero) digits is 8400, while the sum is 31.

The square root of 213078505 is about 14597.2088085360. The cubic root of 213078505 is about 597.2826237265.

The spelling of 213078505 in words is "two hundred thirteen million, seventy-eight thousand, five hundred five".