1628687449 has 3 divisors (see below), whose sum is σ = 1628727807. Its totient is φ = 1628647092.

The previous prime is 1628687387. The next prime is 1628687461. The reversal of 1628687449 is 9447868261.

It is a happy number.

The square root of 1628687449 is 40357.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 9447868261 = 13 ⋅726759097.

It can be written as a sum of positive squares in only one way, i.e., 50055625 + 1578631824 = 7075^2 + 39732^2 .

It is not a de Polignac number, because 1628687449 - 2¹³ = 1628679257 is a prime.

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 1628687449.

It is not an unprimeable number, because it can be changed into a prime (1628687549) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 20179 + ... + 60535.

It is an arithmetic number, because the mean of its divisors is an integer number (542909269).

Almost surely, 2^1628687449 is an apocalyptic number.

1628687449 is the 40357-th square number.

1628687449 is the 20179-th centered octagonal number.

It is an amenable number.

1628687449 is a deficient number, since it is larger than the sum of its proper divisors (40358).

1628687449 is an frugal number, since it uses more digits than its factorization.

1628687449 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80714 (or 40357 counting only the distinct ones).

The product of its digits is 4644864, while the sum is 55.

The cubic root of 1628687449 is about 1176.5559465977. Note that the first 3 decimals are identical.

The spelling of 1628687449 in words is "one billion, six hundred twenty-eight million, six hundred eighty-seven thousand, four hundred forty-nine".