205842422121 has 32 divisors (see below), whose sum is σ = 335285250048. Its totient is φ = 109765983360.

The previous prime is 205842422087. The next prime is 205842422143. The reversal of 205842422121 is 121224248502.

It is not a de Polignac number, because 205842422121 - 2⁶ = 205842422057 is a prime.

It is a super-2 number, since 2×205842422121² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (205842422161) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5177451 + ... + 5217056.

It is an arithmetic number, because the mean of its divisors is an integer number (10477664064).

Almost surely, 2^205842422121 is an apocalyptic number.

205842422121 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

205842422121 is a deficient number, since it is larger than the sum of its proper divisors (129442827927).

205842422121 is a wasteful number, since it uses less digits than its factorization.

205842422121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10394581.

The product of its (nonzero) digits is 20480, while the sum is 33.

The spelling of 205842422121 in words is "two hundred five billion, eight hundred forty-two million, four hundred twenty-two thousand, one hundred twenty-one".