281691031 has 2 divisors, whose sum is σ = 281691032. Its totient is φ = 281691030.

The previous prime is 281691023. The next prime is 281691061. The reversal of 281691031 is 130196182.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 281691031 - 2³ = 281691023 is a prime.

It is a super-2 number, since 2×281691031² = 158699673891685922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 281690984 and 281691002.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (281691061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 140845515 + 140845516.

It is an arithmetic number, because the mean of its divisors is an integer number (140845516).

Almost surely, 2^281691031 is an apocalyptic number.

281691031 is a deficient number, since it is larger than the sum of its proper divisors (1).

281691031 is an equidigital number, since it uses as much as digits as its factorization.

281691031 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2592, while the sum is 31.

The square root of 281691031 is about 16783.6536844633. The cubic root of 281691031 is about 655.5276373132.

The spelling of 281691031 in words is "two hundred eighty-one million, six hundred ninety-one thousand, thirty-one".