681064919421 has 4 divisors (see below), whose sum is σ = 908086559232. Its totient is φ = 454043279612.

The previous prime is 681064919411. The next prime is 681064919429. The reversal of 681064919421 is 124919460186.

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 681064919421 - 2⁶ = 681064919357 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681064919429) 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, 113510819901 + ... + 113510819906.

It is an arithmetic number, because the mean of its divisors is an integer number (227021639808).

Almost surely, 2^681064919421 is an apocalyptic number.

It is an amenable number.

681064919421 is a deficient number, since it is larger than the sum of its proper divisors (227021639811).

681064919421 is a wasteful number, since it uses less digits than its factorization.

681064919421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 227021639810.

The product of its (nonzero) digits is 746496, while the sum is 51.

The spelling of 681064919421 in words is "six hundred eighty-one billion, sixty-four million, nine hundred nineteen thousand, four hundred twenty-one".