212643641 has 4 divisors (see below), whose sum is σ = 243021312. Its totient is φ = 182265972.

The previous prime is 212643637. The next prime is 212643647. The reversal of 212643641 is 146346212.

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 not a de Polignac number, because 212643641 - 2² = 212643637 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (212643647) 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, 15188825 + ... + 15188838.

It is an arithmetic number, because the mean of its divisors is an integer number (60755328).

Almost surely, 2^212643641 is an apocalyptic number.

It is an amenable number.

212643641 is a deficient number, since it is larger than the sum of its proper divisors (30377671).

212643641 is an equidigital number, since it uses as much as digits as its factorization.

212643641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30377670.

The product of its digits is 6912, while the sum is 29.

The square root of 212643641 is about 14582.3057504635. The cubic root of 212643641 is about 596.8760230276.

Adding to 212643641 its reverse (146346212), we get a palindrome (358989853).

The spelling of 212643641 in words is "two hundred twelve million, six hundred forty-three thousand, six hundred forty-one".