561021021 has 24 divisors (see below), whose sum is σ = 889911360. Its totient is φ = 337752000.

The previous prime is 561021007. The next prime is 561021031. The reversal of 561021021 is 120120165.

561021021 is a `hidden beast` number, since 561 + 0 + 2 + 102 + 1 = 666.

It is not a de Polignac number, because 561021021 - 2⁵ = 561020989 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 561020985 and 561021003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (561021001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3816 + ... + 33713.

It is an arithmetic number, because the mean of its divisors is an integer number (37079640).

Almost surely, 2^561021021 is an apocalyptic number.

It is an amenable number.

561021021 is a deficient number, since it is larger than the sum of its proper divisors (328890339).

561021021 is a wasteful number, since it uses less digits than its factorization.

561021021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37697 (or 37694 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 18.

The square root of 561021021 is about 23685.8823141550. The cubic root of 561021021 is about 824.7576985403.

Adding to 561021021 its reverse (120120165), we get a palindrome (681141186).

The spelling of 561021021 in words is "five hundred sixty-one million, twenty-one thousand, twenty-one".