1980880861 has 2 divisors, whose sum is σ = 1980880862. Its totient is φ = 1980880860.

The previous prime is 1980880843. The next prime is 1980880897. The reversal of 1980880861 is 1680880891.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1894947961 + 85932900 = 43531^2 + 9270^2 .

It is a cyclic number.

It is not a de Polignac number, because 1980880861 - 2⁵ = 1980880829 is a prime.

It is a super-2 number, since 2×1980880861² = 7847777970952202642, which contains 22 as substring.

1980880861 is a strobogrammatic number because it is the same when read upside-down.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1980880801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 990440430 + 990440431.

It is an arithmetic number, because the mean of its divisors is an integer number (990440431).

Almost surely, 2^1980880861 is an apocalyptic number.

It is an amenable number.

1980880861 is a deficient number, since it is larger than the sum of its proper divisors (1).

1980880861 is an equidigital number, since it uses as much as digits as its factorization.

1980880861 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 221184, while the sum is 49.

The square root of 1980880861 is about 44507.0877613892. The cubic root of 1980880861 is about 1255.8934207524.

The spelling of 1980880861 in words is "one billion, nine hundred eighty million, eight hundred eighty thousand, eight hundred sixty-one".