1561312461 has 8 divisors (see below), whose sum is σ = 2082797280. Its totient is φ = 1040351312.

The previous prime is 1561312447. The next prime is 1561312483. The reversal of 1561312461 is 1642131651.

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 1561312461 - 2⁵ = 1561312429 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1561312661) 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 7 ways as a sum of consecutive naturals, for example, 123906 + ... + 135923.

It is an arithmetic number, because the mean of its divisors is an integer number (260349660).

Almost surely, 2^1561312461 is an apocalyptic number.

It is an amenable number.

1561312461 is a deficient number, since it is larger than the sum of its proper divisors (521484819).

1561312461 is a wasteful number, since it uses less digits than its factorization.

1561312461 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 261835.

The product of its digits is 4320, while the sum is 30.

The square root of 1561312461 is about 39513.4465846755. The cubic root of 1561312461 is about 1160.1031569478.

The spelling of 1561312461 in words is "one billion, five hundred sixty-one million, three hundred twelve thousand, four hundred sixty-one".