1561167091 has 8 divisors (see below), whose sum is σ = 1792728000. Its totient is φ = 1344545640.

The previous prime is 1561167089. The next prime is 1561167107. The reversal of 1561167091 is 1907611651.

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

It is not a de Polignac number, because 1561167091 - 2¹ = 1561167089 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 1561167091.

It is not an unprimeable number, because it can be changed into a prime (1561167791) 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, 3734641 + ... + 3735058.

It is an arithmetic number, because the mean of its divisors is an integer number (224091000).

Almost surely, 2^1561167091 is an apocalyptic number.

1561167091 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1561167091 is a deficient number, since it is larger than the sum of its proper divisors (231560909).

1561167091 is a wasteful number, since it uses less digits than its factorization.

1561167091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7469729.

The product of its (nonzero) digits is 11340, while the sum is 37.

The square root of 1561167091 is about 39511.6070414758. The cubic root of 1561167091 is about 1160.0671510373.

The spelling of 1561167091 in words is "one billion, five hundred sixty-one million, one hundred sixty-seven thousand, ninety-one".