1561261364 has 24 divisors (see below), whose sum is σ = 2943733800. Its totient is φ = 720249984.

The previous prime is 1561261343. The next prime is 1561261397. The reversal of 1561261364 is 4631621651.

It can be written as a sum of positive squares in 4 ways, for example, as 4169764 + 1557091600 = 2042^2 + 39460^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 134462 + ... + 145610.

It is an arithmetic number, because the mean of its divisors is an integer number (122655575).

Almost surely, 2^1561261364 is an apocalyptic number.

It is an amenable number.

1561261364 is a deficient number, since it is larger than the sum of its proper divisors (1382472436).

1561261364 is a wasteful number, since it uses less digits than its factorization.

1561261364 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13859 (or 13857 counting only the distinct ones).

The product of its digits is 25920, while the sum is 35.

The square root of 1561261364 is about 39512.8000020247. The cubic root of 1561261364 is about 1160.0905012625.

The spelling of 1561261364 in words is "one billion, five hundred sixty-one million, two hundred sixty-one thousand, three hundred sixty-four".