1780769245 has 4 divisors (see below), whose sum is σ = 2136923100. Its totient is φ = 1424615392.

The previous prime is 1780769213. The next prime is 1780769251. The reversal of 1780769245 is 5429670871.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5429670871 = 337 ⋅16111783.

It can be written as a sum of positive squares in 2 ways, for example, as 312193561 + 1468575684 = 17669^2 + 38322^2 .

It is a cyclic number.

It is not a de Polignac number, because 1780769245 - 2⁵ = 1780769213 is a prime.

It is a super-2 number, since 2×1780769245² = 6342278207875740050, which contains 22 as substring.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 178076920 + ... + 178076929.

It is an arithmetic number, because the mean of its divisors is an integer number (534230775).

Almost surely, 2^1780769245 is an apocalyptic number.

It is an amenable number.

1780769245 is a deficient number, since it is larger than the sum of its proper divisors (356153855).

1780769245 is an equidigital number, since it uses as much as digits as its factorization.

1780769245 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 356153854.

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

The square root of 1780769245 is about 42199.1616622890. The cubic root of 1780769245 is about 1212.0928298756.

The spelling of 1780769245 in words is "one billion, seven hundred eighty million, seven hundred sixty-nine thousand, two hundred forty-five".