681131421 has 24 divisors (see below), whose sum is σ = 993152160. Its totient is φ = 449820000.

The previous prime is 681131419. The next prime is 681131441. The reversal of 681131421 is 124131186.

It is a happy number.

It is not a de Polignac number, because 681131421 - 2¹ = 681131419 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681131441) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 475935 + ... + 477363.

It is an arithmetic number, because the mean of its divisors is an integer number (41381340).

Almost surely, 2^681131421 is an apocalyptic number.

It is an amenable number.

681131421 is a deficient number, since it is larger than the sum of its proper divisors (312020739).

681131421 is a wasteful number, since it uses less digits than its factorization.

681131421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1897 (or 1894 counting only the distinct ones).

The product of its digits is 1152, while the sum is 27.

The square root of 681131421 is about 26098.4946117587. The cubic root of 681131421 is about 879.8533764838.

The spelling of 681131421 in words is "six hundred eighty-one million, one hundred thirty-one thousand, four hundred twenty-one".