1771120561 has 4 divisors (see below), whose sum is σ = 2024137792. Its totient is φ = 1518103332.

The previous prime is 1771120553. The next prime is 1771120591. The reversal of 1771120561 is 1650211771.

It is a happy number.

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 a cyclic number.

It is not a de Polignac number, because 1771120561 - 2³ = 1771120553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1771120531) 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, 126508605 + ... + 126508618.

It is an arithmetic number, because the mean of its divisors is an integer number (506034448).

Almost surely, 2^1771120561 is an apocalyptic number.

It is an amenable number.

1771120561 is a deficient number, since it is larger than the sum of its proper divisors (253017231).

1771120561 is an equidigital number, since it uses as much as digits as its factorization.

1771120561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 253017230.

The product of its (nonzero) digits is 2940, while the sum is 31.

The square root of 1771120561 is about 42084.6832113537. The cubic root of 1771120561 is about 1209.8997164344.

The spelling of 1771120561 in words is "one billion, seven hundred seventy-one million, one hundred twenty thousand, five hundred sixty-one".