213444861 has 16 divisors (see below), whose sum is σ = 325484544. Its totient is φ = 121880304.

The previous prime is 213444821. The next prime is 213444883. The reversal of 213444861 is 168444312.

It is not a de Polignac number, because 213444861 - 2¹³ = 213436669 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213444821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 36036 + ... + 41538.

It is an arithmetic number, because the mean of its divisors is an integer number (20342784).

Almost surely, 2^213444861 is an apocalyptic number.

213444861 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

213444861 is a deficient number, since it is larger than the sum of its proper divisors (112039683).

213444861 is a wasteful number, since it uses less digits than its factorization.

213444861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7360.

The product of its digits is 18432, while the sum is 33.

The square root of 213444861 is about 14609.7522566264. The cubic root of 213444861 is about 597.6247398626.

The spelling of 213444861 in words is "two hundred thirteen million, four hundred forty-four thousand, eight hundred sixty-one".