493721681 has 2 divisors, whose sum is σ = 493721682. Its totient is φ = 493721680.

The previous prime is 493721677. The next prime is 493721687. The reversal of 493721681 is 186127394.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 471584656 + 22137025 = 21716^2 + 4705^2 .

It is a cyclic number.

It is not a de Polignac number, because 493721681 - 2² = 493721677 is a prime.

It is a super-2 number, since 2×493721681² = 487522196578931522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (493721687) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 246860840 + 246860841.

It is an arithmetic number, because the mean of its divisors is an integer number (246860841).

Almost surely, 2^493721681 is an apocalyptic number.

It is an amenable number.

493721681 is a deficient number, since it is larger than the sum of its proper divisors (1).

493721681 is an equidigital number, since it uses as much as digits as its factorization.

493721681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 72576, while the sum is 41.

The square root of 493721681 is about 22219.8488068664. The cubic root of 493721681 is about 790.3644534280.

The spelling of 493721681 in words is "four hundred ninety-three million, seven hundred twenty-one thousand, six hundred eighty-one".