681938366 has 4 divisors (see below), whose sum is σ = 1022907552. Its totient is φ = 340969182.

The previous prime is 681938297. The next prime is 681938401. The reversal of 681938366 is 663839186.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 170484590 + ... + 170484593.

It is an arithmetic number, because the mean of its divisors is an integer number (255726888).

Almost surely, 2^681938366 is an apocalyptic number.

681938366 is a deficient number, since it is larger than the sum of its proper divisors (340969186).

681938366 is a wasteful number, since it uses less digits than its factorization.

681938366 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 340969185.

The product of its digits is 1119744, while the sum is 50.

The square root of 681938366 is about 26113.9496438206. The cubic root of 681938366 is about 880.2006971653.

The spelling of 681938366 in words is "six hundred eighty-one million, nine hundred thirty-eight thousand, three hundred sixty-six".