681551894 has 8 divisors (see below), whose sum is σ = 1022676408. Its totient is φ = 340659760.

The previous prime is 681551891. The next prime is 681551903. The reversal of 681551894 is 498155186.

It is a happy number.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681551891) 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, 50567 + ... + 62610.

It is an arithmetic number, because the mean of its divisors is an integer number (127834551).

Almost surely, 2^681551894 is an apocalyptic number.

681551894 is a deficient number, since it is larger than the sum of its proper divisors (341124514).

681551894 is a wasteful number, since it uses less digits than its factorization.

681551894 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116190.

The product of its digits is 345600, while the sum is 47.

The square root of 681551894 is about 26106.5488718827. The cubic root of 681551894 is about 880.0343882912.

The spelling of 681551894 in words is "six hundred eighty-one million, five hundred fifty-one thousand, eight hundred ninety-four".