493897981 has 2 divisors, whose sum is σ = 493897982. Its totient is φ = 493897980.

The previous prime is 493897919. The next prime is 493897993. The reversal of 493897981 is 189798394.

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., 477422500 + 16475481 = 21850^2 + 4059^2 .

It is a cyclic number.

It is not a de Polignac number, because 493897981 - 2⁷ = 493897853 is a prime.

It is a super-2 number, since 2×493897981² = 487870431271752722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (493897081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 246948990 + 246948991.

It is an arithmetic number, because the mean of its divisors is an integer number (246948991).

Almost surely, 2^493897981 is an apocalyptic number.

It is an amenable number.

493897981 is a deficient number, since it is larger than the sum of its proper divisors (1).

493897981 is an equidigital number, since it uses as much as digits as its factorization.

493897981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3919104, while the sum is 58.

The square root of 493897981 is about 22223.8156264850. The cubic root of 493897981 is about 790.4585176726.

The spelling of 493897981 in words is "four hundred ninety-three million, eight hundred ninety-seven thousand, nine hundred eighty-one".