280687720981 has 2 divisors, whose sum is σ = 280687720982. Its totient is φ = 280687720980.

The previous prime is 280687720921. The next prime is 280687720991. The reversal of 280687720981 is 189027786082.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 263430695025 + 17257025956 = 513255^2 + 131366^2 .

It is a cyclic number.

It is not a de Polignac number, because 280687720981 - 2¹⁷ = 280687589909 is a prime.

It is a super-2 number, since 2×280687720981² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (280687720921) 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, 140343860490 + 140343860491.

It is an arithmetic number, because the mean of its divisors is an integer number (140343860491).

Almost surely, 2^280687720981 is an apocalyptic number.

It is an amenable number.

280687720981 is a deficient number, since it is larger than the sum of its proper divisors (1).

280687720981 is an equidigital number, since it uses as much as digits as its factorization.

280687720981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5419008, while the sum is 58.

The spelling of 280687720981 in words is "two hundred eighty billion, six hundred eighty-seven million, seven hundred twenty thousand, nine hundred eighty-one".