681049216 has 16 divisors (see below), whose sum is σ = 1356777990. Its totient is φ = 340524544.

The previous prime is 681049183. The next prime is 681049217. The reversal of 681049216 is 612940186.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 620209216 + 60840000 = 24904^2 + 7800^2 .

It is a tau number, because it is divible by the number of its divisors (16).

It is a super-2 number, since 2×681049216² = 927656069228429312, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (681049217) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2660221 + ... + 2660476.

Almost surely, 2^681049216 is an apocalyptic number.

It is an amenable number.

681049216 is a deficient number, since it is larger than the sum of its proper divisors (675728774).

681049216 is an equidigital number, since it uses as much as digits as its factorization.

681049216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5320711 (or 5320699 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 37.

The square root of 681049216 is about 26096.9196649720. The cubic root of 681049216 is about 879.8179788819.

The spelling of 681049216 in words is "six hundred eighty-one million, forty-nine thousand, two hundred sixteen".