1561231790 has 16 divisors (see below), whose sum is σ = 2825746560. Its totient is φ = 621041760.

The previous prime is 1561231783. The next prime is 1561231799. The reversal of 1561231790 is 971321651.

It is a self number, because there is not a number n which added to its sum of digits gives 1561231790.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1561231799) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 429470 + ... + 433089.

It is an arithmetic number, because the mean of its divisors is an integer number (176609160).

Almost surely, 2^1561231790 is an apocalyptic number.

1561231790 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1561231790 is a deficient number, since it is larger than the sum of its proper divisors (1264514770).

1561231790 is a wasteful number, since it uses less digits than its factorization.

1561231790 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 862747.

The product of its (nonzero) digits is 11340, while the sum is 35.

The square root of 1561231790 is about 39512.4257670926. The cubic root of 1561231790 is about 1160.0831762594.

The spelling of 1561231790 in words is "one billion, five hundred sixty-one million, two hundred thirty-one thousand, seven hundred ninety".