1821880979 has 2 divisors, whose sum is σ = 1821880980. Its totient is φ = 1821880978.

The previous prime is 1821880969. The next prime is 1821880981. The reversal of 1821880979 is 9790881281.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1821880979 is a prime.

Together with 1821880981, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1821880979.

It is not a weakly prime, because it can be changed into another prime (1821880969) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 910940489 + 910940490.

It is an arithmetic number, because the mean of its divisors is an integer number (910940490).

Almost surely, 2^1821880979 is an apocalyptic number.

1821880979 is a deficient number, since it is larger than the sum of its proper divisors (1).

1821880979 is an equidigital number, since it uses as much as digits as its factorization.

1821880979 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 580608, while the sum is 53.

The square root of 1821880979 is about 42683.4977362446. The cubic root of 1821880979 is about 1221.3496170330.

The spelling of 1821880979 in words is "one billion, eight hundred twenty-one million, eight hundred eighty thousand, nine hundred seventy-nine".