40688281 has 4 divisors (see below), whose sum is σ = 41355364. Its totient is φ = 40021200.

The previous prime is 40688251. The next prime is 40688287. The reversal of 40688281 is 18288604.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 9985600 + 30702681 = 3160^2 + 5541^2 .

It is a cyclic number.

It is not a de Polignac number, because 40688281 - 2⁹ = 40687769 is a prime.

It is a super-2 number, since 2×40688281² = 3311072421469922, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 40688281.

It is not an unprimeable number, because it can be changed into a prime (40688287) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 333450 + ... + 333571.

It is an arithmetic number, because the mean of its divisors is an integer number (10338841).

Almost surely, 2^40688281 is an apocalyptic number.

It is an amenable number.

40688281 is a deficient number, since it is larger than the sum of its proper divisors (667083).

40688281 is an equidigital number, since it uses as much as digits as its factorization.

40688281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 667082.

The product of its (nonzero) digits is 24576, while the sum is 37.

The square root of 40688281 is about 6378.7366303995. The cubic root of 40688281 is about 343.9456179808.

The spelling of 40688281 in words is "forty million, six hundred eighty-eight thousand, two hundred eighty-one".