681105021 has 8 divisors (see below), whose sum is σ = 909018240. Its totient is φ = 453630912.

The previous prime is 681105013. The next prime is 681105043. The reversal of 681105021 is 120501186.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 681105021 - 2³ = 681105013 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 681104982 and 681105000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681105011) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 106140 + ... + 112373.

It is an arithmetic number, because the mean of its divisors is an integer number (113627280).

Almost surely, 2^681105021 is an apocalyptic number.

It is an amenable number.

681105021 is a deficient number, since it is larger than the sum of its proper divisors (227913219).

681105021 is a wasteful number, since it uses less digits than its factorization.

681105021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 219555.

The product of its (nonzero) digits is 480, while the sum is 24.

The square root of 681105021 is about 26097.9888305593. The cubic root of 681105021 is about 879.8420089129.

The spelling of 681105021 in words is "six hundred eighty-one million, one hundred five thousand, twenty-one".