2129801561 has 12 divisors (see below), whose sum is σ = 2275948080. Its totient is φ = 1987512120.

The previous prime is 2129801551. The next prime is 2129801617. The reversal of 2129801561 is 1651089212.

It is not a de Polignac number, because 2129801561 - 2¹⁰ = 2129800537 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2129801501) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 72806 + ... + 97776.

It is an arithmetic number, because the mean of its divisors is an integer number (189662340).

Almost surely, 2^2129801561 is an apocalyptic number.

It is an amenable number.

2129801561 is a deficient number, since it is larger than the sum of its proper divisors (146146519).

2129801561 is an equidigital number, since it uses as much as digits as its factorization.

2129801561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25124 (or 25057 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 35.

The square root of 2129801561 is about 46149.7731413709. The cubic root of 2129801561 is about 1286.6083936116.

The spelling of 2129801561 in words is "two billion, one hundred twenty-nine million, eight hundred one thousand, five hundred sixty-one".