205701021 has 18 divisors (see below), whose sum is σ = 299113178. Its totient is φ = 136221120.

The previous prime is 205701007. The next prime is 205701053. The reversal of 205701021 is 120107502.

It can be written as a sum of positive squares in 3 ways, for example, as 16088121 + 189612900 = 4011^2 + 13770^2 .

It is not a de Polignac number, because 205701021 - 2¹³ = 205692829 is a prime.

It is a hoax number, since the sum of its digits (18) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 205700985 and 205701003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205701091) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 488391 + ... + 488811.

Almost surely, 2^205701021 is an apocalyptic number.

It is an amenable number.

205701021 is a deficient number, since it is larger than the sum of its proper divisors (93412157).

205701021 is an equidigital number, since it uses as much as digits as its factorization.

205701021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 893 (or 657 counting only the distinct ones).

The product of its (nonzero) digits is 140, while the sum is 18.

The square root of 205701021 is about 14342.2808855496. The cubic root of 205701021 is about 590.3081996014.

Adding to 205701021 its reverse (120107502), we get a palindrome (325808523).

The spelling of 205701021 in words is "two hundred five million, seven hundred one thousand, twenty-one".