205421401011 has 16 divisors (see below), whose sum is σ = 278412363008. Its totient is φ = 134689456800.

The previous prime is 205421400997. The next prime is 205421401013. The reversal of 205421401011 is 110104124502.

It is not a de Polignac number, because 205421401011 - 2¹⁰ = 205421399987 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (205421401013) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2054010 + ... + 2151696.

It is an arithmetic number, because the mean of its divisors is an integer number (17400772688).

Almost surely, 2^205421401011 is an apocalyptic number.

205421401011 is a deficient number, since it is larger than the sum of its proper divisors (72990961997).

205421401011 is a wasteful number, since it uses less digits than its factorization.

205421401011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 109242.

The product of its (nonzero) digits is 320, while the sum is 21.

Adding to 205421401011 its reverse (110104124502), we get a palindrome (315525525513).

The spelling of 205421401011 in words is "two hundred five billion, four hundred twenty-one million, four hundred one thousand, eleven".