681435987 has 8 divisors (see below), whose sum is σ = 912549840. Its totient is φ = 452306400.

The previous prime is 681435977. The next prime is 681436003. The reversal of 681435987 is 789534186.

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

It is not a de Polignac number, because 681435987 - 2¹¹ = 681433939 is a prime.

It is not an unprimeable number, because it can be changed into a prime (681435917) 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, 495264 + ... + 496637.

It is an arithmetic number, because the mean of its divisors is an integer number (114068730).

Almost surely, 2^681435987 is an apocalyptic number.

681435987 is a deficient number, since it is larger than the sum of its proper divisors (231113853).

681435987 is a wasteful number, since it uses less digits than its factorization.

681435987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 992133.

The product of its digits is 1451520, while the sum is 51.

The square root of 681435987 is about 26104.3288938827. The cubic root of 681435987 is about 879.9844982634.

The spelling of 681435987 in words is "six hundred eighty-one million, four hundred thirty-five thousand, nine hundred eighty-seven".