681571428 has 48 divisors (see below), whose sum is σ = 1605851520. Its totient is φ = 224985600.

The previous prime is 681571421. The next prime is 681571433. The reversal of 681571428 is 824175186.

It is a super-2 number, since 2×681571428² = 929079222931918368, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 681571428.

It is not an unprimeable number, because it can be changed into a prime (681571421) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 674988 + ... + 675996.

It is an arithmetic number, because the mean of its divisors is an integer number (33455240).

Almost surely, 2^681571428 is an apocalyptic number.

It is an amenable number.

681571428 is an abundant number, since it is smaller than the sum of its proper divisors (924280092).

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

681571428 is a wasteful number, since it uses less digits than its factorization.

681571428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1508 (or 1506 counting only the distinct ones).

The product of its digits is 107520, while the sum is 42.

The square root of 681571428 is about 26106.9229898891. The cubic root of 681571428 is about 880.0427957838.

The spelling of 681571428 in words is "six hundred eighty-one million, five hundred seventy-one thousand, four hundred twenty-eight".