213959561 has 4 divisors (see below), whose sum is σ = 214053072. Its totient is φ = 213866052.

The previous prime is 213959539. The next prime is 213959563. The reversal of 213959561 is 165959312.

It is a happy number.

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 213959561 - 2¹⁸ = 213697417 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (213959563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 43235 + ... + 47928.

It is an arithmetic number, because the mean of its divisors is an integer number (53513268).

Almost surely, 2^213959561 is an apocalyptic number.

It is an amenable number.

213959561 is a deficient number, since it is larger than the sum of its proper divisors (93511).

213959561 is an equidigital number, since it uses as much as digits as its factorization.

213959561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 93510.

The product of its digits is 72900, while the sum is 41.

The square root of 213959561 is about 14627.3565964599. The cubic root of 213959561 is about 598.1047241490.

The spelling of 213959561 in words is "two hundred thirteen million, nine hundred fifty-nine thousand, five hundred sixty-one".