2026991561 has 4 divisors (see below), whose sum is σ = 2316561792. Its totient is φ = 1737421332.

The previous prime is 2026991557. The next prime is 2026991563. The reversal of 2026991561 is 1651996202.

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 2026991561 - 2² = 2026991557 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (2026991563) 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, 144785105 + ... + 144785118.

It is an arithmetic number, because the mean of its divisors is an integer number (579140448).

Almost surely, 2^2026991561 is an apocalyptic number.

It is an amenable number.

2026991561 is a deficient number, since it is larger than the sum of its proper divisors (289570231).

2026991561 is an equidigital number, since it uses as much as digits as its factorization.

2026991561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 289570230.

The product of its (nonzero) digits is 58320, while the sum is 41.

The square root of 2026991561 is about 45022.1230174678. The cubic root of 2026991561 is about 1265.5636145534.

The spelling of 2026991561 in words is "two billion, twenty-six million, nine hundred ninety-one thousand, five hundred sixty-one".