1978550281 has 2 divisors, whose sum is σ = 1978550282. Its totient is φ = 1978550280.

The previous prime is 1978550279. The next prime is 1978550333. The reversal of 1978550281 is 1820558791.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1819790281 + 158760000 = 42659^2 + 12600^2 .

It is an emirp because it is prime and its reverse (1820558791) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1978550281 - 2¹ = 1978550279 is a prime.

It is a super-2 number, since 2×1978550281² = 7829322428890357922, which contains 22 as substring.

Together with 1978550279, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1978550221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 989275140 + 989275141.

It is an arithmetic number, because the mean of its divisors is an integer number (989275141).

Almost surely, 2^1978550281 is an apocalyptic number.

It is an amenable number.

1978550281 is a deficient number, since it is larger than the sum of its proper divisors (1).

1978550281 is an equidigital number, since it uses as much as digits as its factorization.

1978550281 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 201600, while the sum is 46.

The square root of 1978550281 is about 44480.8979338322. The cubic root of 1978550281 is about 1255.4006923591.

The spelling of 1978550281 in words is "one billion, nine hundred seventy-eight million, five hundred fifty thousand, two hundred eighty-one".