4020561 has 12 divisors (see below), whose sum is σ = 6060288. Its totient is φ = 2563704.

The previous prime is 4020529. The next prime is 4020563. The reversal of 4020561 is 1650204.

It is a happy number.

It is not a de Polignac number, because 4020561 - 2⁵ = 4020529 is a prime.

It is not an unprimeable number, because it can be changed into a prime (4020563) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9505 + ... + 9918.

It is an arithmetic number, because the mean of its divisors is an integer number (505024).

Almost surely, 2^4020561 is an apocalyptic number.

It is an amenable number.

4020561 is a deficient number, since it is larger than the sum of its proper divisors (2039727).

4020561 is a wasteful number, since it uses less digits than its factorization.

4020561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19452 (or 19449 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 4020561 is about 2005.1336613802. The cubic root of 4020561 is about 159.0116284364.

Adding to 4020561 its reverse (1650204), we get a palindrome (5670765).

The spelling of 4020561 in words is "four million, twenty thousand, five hundred sixty-one".