681394133 has 4 divisors (see below), whose sum is σ = 778736160. Its totient is φ = 584052108.

The previous prime is 681394069. The next prime is 681394201. The reversal of 681394133 is 331493186.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 681394133 - 2⁶ = 681394069 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681394033) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 48671003 + ... + 48671016.

It is an arithmetic number, because the mean of its divisors is an integer number (194684040).

Almost surely, 2^681394133 is an apocalyptic number.

It is an amenable number.

681394133 is a deficient number, since it is larger than the sum of its proper divisors (97342027).

681394133 is an equidigital number, since it uses as much as digits as its factorization.

681394133 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97342026.

The product of its digits is 46656, while the sum is 38.

The square root of 681394133 is about 26103.5272137694. The cubic root of 681394133 is about 879.9664815918.

The spelling of 681394133 in words is "six hundred eighty-one million, three hundred ninety-four thousand, one hundred thirty-three".