1561695949 has 8 divisors (see below), whose sum is σ = 1704329280. Its totient is φ = 1419172800.

The previous prime is 1561695943. The next prime is 1561695979. The reversal of 1561695949 is 9495961651.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1561695949 - 2⁵ = 1561695917 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 1561695949.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1561695943) by changing a digit.

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, 3637 + ... + 56005.

It is an arithmetic number, because the mean of its divisors is an integer number (213041160).

Almost surely, 2^1561695949 is an apocalyptic number.

It is an amenable number.

1561695949 is a deficient number, since it is larger than the sum of its proper divisors (142633331).

1561695949 is a wasteful number, since it uses less digits than its factorization.

1561695949 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55091.

The product of its digits is 2624400, while the sum is 55.

The square root of 1561695949 is about 39518.2989132883. The cubic root of 1561695949 is about 1160.1981302969.

The spelling of 1561695949 in words is "one billion, five hundred sixty-one million, six hundred ninety-five thousand, nine hundred forty-nine".