213545861 has 4 divisors (see below), whose sum is σ = 214960224. Its totient is φ = 212131500.

The previous prime is 213545809. The next prime is 213545867. The reversal of 213545861 is 168545312.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 213545861 - 2⁶ = 213545797 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213545867) 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, 706955 + ... + 707256.

It is an arithmetic number, because the mean of its divisors is an integer number (53740056).

Almost surely, 2^213545861 is an apocalyptic number.

It is an amenable number.

213545861 is a deficient number, since it is larger than the sum of its proper divisors (1414363).

213545861 is a wasteful number, since it uses less digits than its factorization.

213545861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1414362.

The product of its digits is 28800, while the sum is 35.

The square root of 213545861 is about 14613.2084430490. The cubic root of 213545861 is about 597.7189883730.

The spelling of 213545861 in words is "two hundred thirteen million, five hundred forty-five thousand, eight hundred sixty-one".