1561039403 has 24 divisors (see below), whose sum is σ = 1988481024. Its totient is φ = 1211792400.

The previous prime is 1561039397. The next prime is 1561039421. The reversal of 1561039403 is 3049301651.

It is not a de Polignac number, because 1561039403 - 2⁶ = 1561039339 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1561039403.

It is not an unprimeable number, because it can be changed into a prime (1561039483) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 140726 + ... + 151412.

It is an arithmetic number, because the mean of its divisors is an integer number (82853376).

Almost surely, 2^1561039403 is an apocalyptic number.

1561039403 is a deficient number, since it is larger than the sum of its proper divisors (427441621).

1561039403 is a wasteful number, since it uses less digits than its factorization.

1561039403 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10983 (or 10976 counting only the distinct ones).

The product of its (nonzero) digits is 9720, while the sum is 32.

The square root of 1561039403 is about 39509.9911794473. The cubic root of 1561039403 is about 1160.0355228420.

The spelling of 1561039403 in words is "one billion, five hundred sixty-one million, thirty-nine thousand, four hundred three".