1561193790 has 128 divisors (see below), whose sum is σ = 4199731200. Its totient is φ = 368824320.

The previous prime is 1561193789. The next prime is 1561193797. The reversal of 1561193790 is 973911651.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1561193797) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1680046 + ... + 1680974.

It is an arithmetic number, because the mean of its divisors is an integer number (32810400).

Almost surely, 2^1561193790 is an apocalyptic number.

1561193790 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1561193790, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2099865600).

1561193790 is an abundant number, since it is smaller than the sum of its proper divisors (2638537410).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1561193790 is a wasteful number, since it uses less digits than its factorization.

1561193790 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1122.

The product of its (nonzero) digits is 51030, while the sum is 42.

The square root of 1561193790 is about 39511.9449027759. The cubic root of 1561193790 is about 1160.0737641360.

The spelling of 1561193790 in words is "one billion, five hundred sixty-one million, one hundred ninety-three thousand, seven hundred ninety".