205101421 has 4 divisors (see below), whose sum is σ = 234401632. Its totient is φ = 175801212.

The previous prime is 205101401. The next prime is 205101431. The reversal of 205101421 is 124101502.

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 a de Polignac number, because none of the positive numbers 2^k-205101421 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 205101395 and 205101404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205101401) 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, 14650095 + ... + 14650108.

It is an arithmetic number, because the mean of its divisors is an integer number (58600408).

Almost surely, 2^205101421 is an apocalyptic number.

It is an amenable number.

205101421 is a deficient number, since it is larger than the sum of its proper divisors (29300211).

205101421 is an equidigital number, since it uses as much as digits as its factorization.

205101421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29300210.

The product of its (nonzero) digits is 80, while the sum is 16.

The square root of 205101421 is about 14321.3624002746. The cubic root of 205101421 is about 589.7340762736.

Adding to 205101421 its reverse (124101502), we get a palindrome (329202923).

The spelling of 205101421 in words is "two hundred five million, one hundred one thousand, four hundred twenty-one".