681395045 has 4 divisors (see below), whose sum is σ = 817674060. Its totient is φ = 545116032.

The previous prime is 681395041. The next prime is 681395051. The reversal of 681395045 is 540593186.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 373532929 + 307862116 = 19327^2 + 17546^2 .

It is a cyclic number.

It is not a de Polignac number, because 681395045 - 2² = 681395041 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 681394993 and 681395011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681395041) 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, 68139500 + ... + 68139509.

It is an arithmetic number, because the mean of its divisors is an integer number (204418515).

Almost surely, 2^681395045 is an apocalyptic number.

It is an amenable number.

681395045 is a deficient number, since it is larger than the sum of its proper divisors (136279015).

681395045 is a wasteful number, since it uses less digits than its factorization.

681395045 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 136279014.

The product of its (nonzero) digits is 129600, while the sum is 41.

The square root of 681395045 is about 26103.5446826671. The cubic root of 681395045 is about 879.9668741835.

The spelling of 681395045 in words is "six hundred eighty-one million, three hundred ninety-five thousand, forty-five".