681001216 has 81 divisors (see below), whose sum is σ = 1588091421. Its totient is φ = 290605056.

The previous prime is 681001213. The next prime is 681001219. The reversal of 681001216 is 612100186.

The square root of 681001216 is 26096.

It is a perfect power (a square), and thus also a powerful number.

It is an interprime number because it is at equal distance from previous prime (681001213) and next prime (681001219).

It can be written as a sum of positive squares in only one way, i.e., 138297600 + 542703616 = 11760^2 + 23296^2 .

It is not an unprimeable number, because it can be changed into a prime (681001213) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 2922636 + ... + 2922868.

Almost surely, 2^681001216 is an apocalyptic number.

681001216 is the 26096-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 681001216

681001216 is an abundant number, since it is smaller than the sum of its proper divisors (907090205).

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

681001216 is an frugal number, since it uses more digits than its factorization.

681001216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 496 (or 242 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 25.

The cubic root of 681001216 is about 879.7973086894.

Multiplying 681001216 by its sum of digits (25), we get a square (17025030400 = 130480²).

Multiplying 681001216 by its product of nonzero digits (576), we get a square (392256700416 = 626304²).

The spelling of 681001216 in words is "six hundred eighty-one million, one thousand, two hundred sixteen".