1608440261 has 4 divisors (see below), whose sum is σ = 1703054412. Its totient is φ = 1513826112.

The previous prime is 1608440243. The next prime is 1608440263. The reversal of 1608440261 is 1620448061.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1620448061 = 277 ⋅5849993.

It can be written as a sum of positive squares in 2 ways, for example, as 1004509636 + 603930625 = 31694^2 + 24575^2 .

It is a cyclic number.

It is not a de Polignac number, because 1608440261 - 2²⁶ = 1541331397 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1608440263) 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, 47307050 + ... + 47307083.

It is an arithmetic number, because the mean of its divisors is an integer number (425763603).

Almost surely, 2^1608440261 is an apocalyptic number.

It is an amenable number.

1608440261 is a deficient number, since it is larger than the sum of its proper divisors (94614151).

1608440261 is an equidigital number, since it uses as much as digits as its factorization.

1608440261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94614150.

The product of its (nonzero) digits is 9216, while the sum is 32.

The square root of 1608440261 is about 40105.3644915490. The cubic root of 1608440261 is about 1171.6601122460.

The spelling of 1608440261 in words is "one billion, six hundred eight million, four hundred forty thousand, two hundred sixty-one".