681564740 has 24 divisors (see below), whose sum is σ = 1440898200. Its totient is φ = 270795008.

The previous prime is 681564733. The next prime is 681564761. The reversal of 681564740 is 47465186.

681564740 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 73547776 + 608016964 = 8576^2 + 24658^2 .

It is a super-2 number, since 2×681564740² = 929060989622535200, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 111377 + ... + 117336.

It is an arithmetic number, because the mean of its divisors is an integer number (60037425).

Almost surely, 2^681564740 is an apocalyptic number.

It is an amenable number.

681564740 is an abundant number, since it is smaller than the sum of its proper divisors (759333460).

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

681564740 is a wasteful number, since it uses less digits than its factorization.

681564740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 228871 (or 228869 counting only the distinct ones).

The product of its (nonzero) digits is 161280, while the sum is 41.

The square root of 681564740 is about 26106.7949009448. The cubic root of 681564740 is about 880.0399172664.

The spelling of 681564740 in words is "six hundred eighty-one million, five hundred sixty-four thousand, seven hundred forty".