2181836477 has 2 divisors, whose sum is σ = 2181836478. Its totient is φ = 2181836476.

The previous prime is 2181836453. The next prime is 2181836479. The reversal of 2181836477 is 7746381812.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2117932441 + 63904036 = 46021^2 + 7994^2 .

It is a cyclic number.

It is not a de Polignac number, because 2181836477 - 2¹² = 2181832381 is a prime.

Together with 2181836479, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2181836479) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1090918238 + 1090918239.

It is an arithmetic number, because the mean of its divisors is an integer number (1090918239).

Almost surely, 2^2181836477 is an apocalyptic number.

It is an amenable number.

2181836477 is a deficient number, since it is larger than the sum of its proper divisors (1).

2181836477 is an equidigital number, since it uses as much as digits as its factorization.

2181836477 is an evil number, because the sum of its binary digits is even.

The product of its digits is 451584, while the sum is 47.

The square root of 2181836477 is about 46710.1324875021. The cubic root of 2181836477 is about 1297.0022597232.

The spelling of 2181836477 in words is "two billion, one hundred eighty-one million, eight hundred thirty-six thousand, four hundred seventy-seven".