280681993 has 2 divisors, whose sum is σ = 280681994. Its totient is φ = 280681992.

The previous prime is 280681969. The next prime is 280682033. The reversal of 280681993 is 399186082.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 238795209 + 41886784 = 15453^2 + 6472^2 .

It is a cyclic number.

It is not a de Polignac number, because 280681993 - 2²⁵ = 247127561 is a prime.

It is not a weakly prime, because it can be changed into another prime (280681493) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 140340996 + 140340997.

It is an arithmetic number, because the mean of its divisors is an integer number (140340997).

Almost surely, 2^280681993 is an apocalyptic number.

It is an amenable number.

280681993 is a deficient number, since it is larger than the sum of its proper divisors (1).

280681993 is an equidigital number, since it uses as much as digits as its factorization.

280681993 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 186624, while the sum is 46.

The square root of 280681993 is about 16753.5665755086. The cubic root of 280681993 is about 654.7439847897.

The spelling of 280681993 in words is "two hundred eighty million, six hundred eighty-one thousand, nine hundred ninety-three".