1511441561 has 4 divisors (see below), whose sum is σ = 1727361792. Its totient is φ = 1295521332.

The previous prime is 1511441551. The next prime is 1511441579. The reversal of 1511441561 is 1651441151.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 1511441561 - 2²⁶ = 1444332697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1511441501) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 107960105 + ... + 107960118.

It is an arithmetic number, because the mean of its divisors is an integer number (431840448).

Almost surely, 2^1511441561 is an apocalyptic number.

It is an amenable number.

1511441561 is a deficient number, since it is larger than the sum of its proper divisors (215920231).

1511441561 is an equidigital number, since it uses as much as digits as its factorization.

1511441561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 215920230.

The product of its digits is 2400, while the sum is 29.

The square root of 1511441561 is about 38877.2627765896. The cubic root of 1511441561 is about 1147.6173886423.

The spelling of 1511441561 in words is "one billion, five hundred eleven million, four hundred forty-one thousand, five hundred sixty-one".