681666995520 has 1120 divisors, whose sum is σ = 3029300398080. Its totient is φ = 141893959680.

The previous prime is 681666995509. The next prime is 681666995531. The reversal of 681666995520 is 25599666186.

It is an interprime number because it is at equal distance from previous prime (681666995509) and next prime (681666995531).

It is a tau number, because it is divible by the number of its divisors (1120).

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 95615316 + ... + 95622444.

Almost surely, 2^681666995520 is an apocalyptic number.

681666995520 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 681666995520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1514650199040).

681666995520 is an abundant number, since it is smaller than the sum of its proper divisors (2347633402560).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

681666995520 is a wasteful number, since it uses less digits than its factorization.

681666995520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7213 (or 7194 counting only the distinct ones).

The product of its (nonzero) digits is 41990400, while the sum is 63.

The spelling of 681666995520 in words is "six hundred eighty-one billion, six hundred sixty-six million, nine hundred ninety-five thousand, five hundred twenty".