681465408 has 224 divisors, whose sum is σ = 2049621504. Its totient is φ = 198402048.

The previous prime is 681465401. The next prime is 681465409. The reversal of 681465408 is 804564186.

It is a self number, because there is not a number n which added to its sum of digits gives 681465408.

It is not an unprimeable number, because it can be changed into a prime (681465401) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4340466 + ... + 4340622.

It is an arithmetic number, because the mean of its divisors is an integer number (9150096).

Almost surely, 2^681465408 is an apocalyptic number.

681465408 is the 15072-nd octagonal number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 681465408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1024810752).

681465408 is an abundant number, since it is smaller than the sum of its proper divisors (1368156096).

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

681465408 is a wasteful number, since it uses less digits than its factorization.

681465408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 269 (or 259 counting only the distinct ones).

The product of its (nonzero) digits is 184320, while the sum is 42.

The square root of 681465408 is about 26104.8924150244. The cubic root of 681465408 is about 879.9971625253.

The spelling of 681465408 in words is "six hundred eighty-one million, four hundred sixty-five thousand, four hundred eight".