4020202561 has 4 divisors (see below), whose sum is σ = 4118256324. Its totient is φ = 3922148800.

The previous prime is 4020202547. The next prime is 4020202663. The reversal of 4020202561 is 1652020204.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 708890625 + 3311311936 = 26625^2 + 57544^2 .

It is a cyclic number.

It is not a de Polignac number, because 4020202561 - 2²⁵ = 3986648129 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (4020202531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 49026820 + ... + 49026901.

It is an arithmetic number, because the mean of its divisors is an integer number (1029564081).

Almost surely, 2^4020202561 is an apocalyptic number.

4020202561 is a gapful number since it is divisible by the number (41) formed by its first and last digit.

It is an amenable number.

4020202561 is a deficient number, since it is larger than the sum of its proper divisors (98053763).

4020202561 is an equidigital number, since it uses as much as digits as its factorization.

4020202561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98053762.

The product of its (nonzero) digits is 960, while the sum is 22.

The square root of 4020202561 is about 63405.0673132676. The cubic root of 4020202561 is about 1590.0690292144.

Adding to 4020202561 its reverse (1652020204), we get a palindrome (5672222765).

The spelling of 4020202561 in words is "four billion, twenty million, two hundred two thousand, five hundred sixty-one".