681421647 has 16 divisors (see below), whose sum is σ = 919974240. Its totient is φ = 448588800.

The previous prime is 681421619. The next prime is 681421673. The reversal of 681421647 is 746124186.

It is not a de Polignac number, because 681421647 - 2²⁷ = 547203919 is a prime.

It is a super-2 number, since 2×681421647² = 928670922000385218, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681421607) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 314247 + ... + 316407.

It is an arithmetic number, because the mean of its divisors is an integer number (57498390).

Almost surely, 2^681421647 is an apocalyptic number.

681421647 is a deficient number, since it is larger than the sum of its proper divisors (238552593).

681421647 is a wasteful number, since it uses less digits than its factorization.

681421647 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3434.

The product of its digits is 64512, while the sum is 39.

The square root of 681421647 is about 26104.0542253497. The cubic root of 681421647 is about 879.9783254820.

The spelling of 681421647 in words is "six hundred eighty-one million, four hundred twenty-one thousand, six hundred forty-seven".