280990993 has 2 divisors, whose sum is σ = 280990994. Its totient is φ = 280990992.

The previous prime is 280990891. The next prime is 280991003. The reversal of 280990993 is 399099082.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 268402689 + 12588304 = 16383^2 + 3548^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-280990993 is a prime.

It is not a weakly prime, because it can be changed into another prime (280996993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 140495496 + 140495497.

It is an arithmetic number, because the mean of its divisors is an integer number (140495497).

Almost surely, 2^280990993 is an apocalyptic number.

It is an amenable number.

280990993 is a deficient number, since it is larger than the sum of its proper divisors (1).

280990993 is an equidigital number, since it uses as much as digits as its factorization.

280990993 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 314928, while the sum is 49.

The square root of 280990993 is about 16762.7859558010. The cubic root of 280990993 is about 654.9841637101.

The spelling of 280990993 in words is "two hundred eighty million, nine hundred ninety thousand, nine hundred ninety-three".