281628961 has 2 divisors, whose sum is σ = 281628962. Its totient is φ = 281628960.

The previous prime is 281628931. The next prime is 281628983. The reversal of 281628961 is 169826182.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 214798336 + 66830625 = 14656^2 + 8175^2 .

It is a cyclic number.

It is not a de Polignac number, because 281628961 - 2⁵ = 281628929 is a prime.

It is not a weakly prime, because it can be changed into another prime (281628901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 140814480 + 140814481.

It is an arithmetic number, because the mean of its divisors is an integer number (140814481).

Almost surely, 2^281628961 is an apocalyptic number.

It is an amenable number.

281628961 is a deficient number, since it is larger than the sum of its proper divisors (1).

281628961 is an equidigital number, since it uses as much as digits as its factorization.

281628961 is an evil number, because the sum of its binary digits is even.

The product of its digits is 82944, while the sum is 43.

The square root of 281628961 is about 16781.8044619761. The cubic root of 281628961 is about 655.4794857513.

The spelling of 281628961 in words is "two hundred eighty-one million, six hundred twenty-eight thousand, nine hundred sixty-one".