561521403 has 30 divisors (see below), whose sum is σ = 868843404. Its totient is φ = 361395216.

The previous prime is 561521399. The next prime is 561521419. The reversal of 561521403 is 304125165.

561521403 is a `hidden beast` number, since 5 + 615 + 2 + 1 + 40 + 3 = 666.

561521403 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 561521403 - 2² = 561521399 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (561521423) by changing a digit.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 64000 + ... + 72242.

Almost surely, 2^561521403 is an apocalyptic number.

561521403 is a deficient number, since it is larger than the sum of its proper divisors (307322001).

561521403 is an equidigital number, since it uses as much as digits as its factorization.

561521403 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8313 (or 8275 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 27.

The square root of 561521403 is about 23696.4428343159. The cubic root of 561521403 is about 825.0028297424.

Adding to 561521403 its reverse (304125165), we get a palindrome (865646568).

The spelling of 561521403 in words is "five hundred sixty-one million, five hundred twenty-one thousand, four hundred three".