681183493 has 2 divisors, whose sum is σ = 681183494. Its totient is φ = 681183492.

The previous prime is 681183469. The next prime is 681183509. The reversal of 681183493 is 394381186.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 643028164 + 38155329 = 25358^2 + 6177^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-681183493 is a prime.

It is a super-2 number, since 2×681183493² = 928021902271362098, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (681183463) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 340591746 + 340591747.

It is an arithmetic number, because the mean of its divisors is an integer number (340591747).

Almost surely, 2^681183493 is an apocalyptic number.

It is an amenable number.

681183493 is a deficient number, since it is larger than the sum of its proper divisors (1).

681183493 is an equidigital number, since it uses as much as digits as its factorization.

681183493 is an evil number, because the sum of its binary digits is even.

The product of its digits is 124416, while the sum is 43.

The square root of 681183493 is about 26099.4921981252. The cubic root of 681183493 is about 879.8757972953.

The spelling of 681183493 in words is "six hundred eighty-one million, one hundred eighty-three thousand, four hundred ninety-three".