213440861 has 4 divisors (see below), whose sum is σ = 214873500. Its totient is φ = 212008224.

The previous prime is 213440849. The next prime is 213440873. The reversal of 213440861 is 168044312.

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 (213440849) and next prime (213440873).

It can be written as a sum of positive squares in 2 ways, for example, as 22033636 + 191407225 = 4694^2 + 13835^2 .

It is a cyclic number.

It is not a de Polignac number, because 213440861 - 2¹⁸ = 213178717 is a prime.

It is a super-2 number, since 2×213440861² = 91114002288842642, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213440881) 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, 716096 + ... + 716393.

It is an arithmetic number, because the mean of its divisors is an integer number (53718375).

Almost surely, 2^213440861 is an apocalyptic number.

It is an amenable number.

213440861 is a deficient number, since it is larger than the sum of its proper divisors (1432639).

213440861 is a wasteful number, since it uses less digits than its factorization.

213440861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1432638.

The product of its (nonzero) digits is 4608, while the sum is 29.

The square root of 213440861 is about 14609.6153611243. The cubic root of 213440861 is about 597.6210066363.

The spelling of 213440861 in words is "two hundred thirteen million, four hundred forty thousand, eight hundred sixty-one".