1780649725 has 6 divisors (see below), whose sum is σ = 2208005690. Its totient is φ = 1424519760.

The previous prime is 1780649711. The next prime is 1780649743. The reversal of 1780649725 is 5279460871.

It can be written as a sum of positive squares in 3 ways, for example, as 454670329 + 1325979396 = 21323^2 + 36414^2 .

It is not a de Polignac number, because 1780649725 - 2¹⁷ = 1780518653 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 35612970 + ... + 35613019.

Almost surely, 2^1780649725 is an apocalyptic number.

It is an amenable number.

1780649725 is a deficient number, since it is larger than the sum of its proper divisors (427355965).

1780649725 is an equidigital number, since it uses as much as digits as its factorization.

1780649725 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71225999 (or 71225994 counting only the distinct ones).

The product of its (nonzero) digits is 846720, while the sum is 49.

The square root of 1780649725 is about 42197.7454966495. The cubic root of 1780649725 is about 1212.0657118990.

The spelling of 1780649725 in words is "one billion, seven hundred eighty million, six hundred forty-nine thousand, seven hundred twenty-five".