681339242 has 4 divisors (see below), whose sum is σ = 1022008866. Its totient is φ = 340669620.

The previous prime is 681339229. The next prime is 681339247. The reversal of 681339242 is 242933186.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 242933186 = 2 ⋅121466593.

It can be written as a sum of positive squares in only one way, i.e., 424730881 + 256608361 = 20609^2 + 16019^2 .

It is a junction number, because it is equal to n+sod(n) for n = 681339196 and 681339205.

It is not an unprimeable number, because it can be changed into a prime (681339247) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 170334809 + ... + 170334812.

Almost surely, 2^681339242 is an apocalyptic number.

681339242 is a deficient number, since it is larger than the sum of its proper divisors (340669624).

681339242 is a wasteful number, since it uses less digits than its factorization.

681339242 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 340669623.

The product of its digits is 62208, while the sum is 38.

The square root of 681339242 is about 26102.4757829597. The cubic root of 681339242 is about 879.9428518329.

The spelling of 681339242 in words is "six hundred eighty-one million, three hundred thirty-nine thousand, two hundred forty-two".