1561488971 has 8 divisors (see below), whose sum is σ = 1826060544. Its totient is φ = 1307292840.

The previous prime is 1561488967. The next prime is 1561488979. The reversal of 1561488971 is 1798841651.

It is a happy number.

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

It is not a de Polignac number, because 1561488971 - 2² = 1561488967 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1561488979) 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, 2593535 + ... + 2594136.

It is an arithmetic number, because the mean of its divisors is an integer number (228257568).

Almost surely, 2^1561488971 is an apocalyptic number.

1561488971 is a deficient number, since it is larger than the sum of its proper divisors (264571573).

1561488971 is an equidigital number, since it uses as much as digits as its factorization.

1561488971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5187721.

The product of its digits is 483840, while the sum is 50.

The square root of 1561488971 is about 39515.6800650071. The cubic root of 1561488971 is about 1160.1468727526.

The spelling of 1561488971 in words is "one billion, five hundred sixty-one million, four hundred eighty-eight thousand, nine hundred seventy-one".