681891220395 has 384 divisors, whose sum is σ = 1613695426560. Its totient is φ = 269637984000.

The previous prime is 681891220363. The next prime is 681891220477. The reversal of 681891220395 is 593022198186.

681891220395 is a `hidden beast` number, since 68 + 189 + 12 + 2 + 0 + 395 = 666.

It is not a de Polignac number, because 681891220395 - 2⁵ = 681891220363 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 383 ways as a sum of consecutive naturals, for example, 353127580 + ... + 353129510.

It is an arithmetic number, because the mean of its divisors is an integer number (4202331840).

Almost surely, 2^681891220395 is an apocalyptic number.

681891220395 is an abundant number, since it is smaller than the sum of its proper divisors (931804206165).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

681891220395 is a wasteful number, since it uses less digits than its factorization.

681891220395 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2204 (or 2191 counting only the distinct ones).

The product of its (nonzero) digits is 1866240, while the sum is 54.

The spelling of 681891220395 in words is "six hundred eighty-one billion, eight hundred ninety-one million, two hundred twenty thousand, three hundred ninety-five".