681732538 has 8 divisors (see below), whose sum is σ = 1082751732. Its totient is φ = 320815296.

The previous prime is 681732517. The next prime is 681732539. The reversal of 681732538 is 835237186.

It can be written as a sum of positive squares in 2 ways, for example, as 676364049 + 5368489 = 26007^2 + 2317^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 681732494 and 681732503.

It is not an unprimeable number, because it can be changed into a prime (681732539) 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, 10025445 + ... + 10025512.

Almost surely, 2^681732538 is an apocalyptic number.

681732538 is a deficient number, since it is larger than the sum of its proper divisors (401019194).

681732538 is a wasteful number, since it uses less digits than its factorization.

681732538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20050976.

The product of its digits is 241920, while the sum is 43.

The square root of 681732538 is about 26110.0083875896. The cubic root of 681732538 is about 880.1121318889.

The spelling of 681732538 in words is "six hundred eighty-one million, seven hundred thirty-two thousand, five hundred thirty-eight".