211405512421 has 4 divisors (see below), whose sum is σ = 211410137344. Its totient is φ = 211400887500.

The previous prime is 211405512401. The next prime is 211405512509. The reversal of 211405512421 is 124215504112.

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 211405512421 - 2¹³ = 211405504229 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 211405512421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211405512401) 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 3 ways as a sum of consecutive naturals, for example, 2243205 + ... + 2335546.

It is an arithmetic number, because the mean of its divisors is an integer number (52852534336).

Almost surely, 2^211405512421 is an apocalyptic number.

It is an amenable number.

211405512421 is a deficient number, since it is larger than the sum of its proper divisors (4624923).

211405512421 is an equidigital number, since it uses as much as digits as its factorization.

211405512421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4624922.

The product of its (nonzero) digits is 3200, while the sum is 28.

The spelling of 211405512421 in words is "two hundred eleven billion, four hundred five million, five hundred twelve thousand, four hundred twenty-one".