7780023649 has 4 divisors (see below), whose sum is σ = 7808945940. Its totient is φ = 7751101360.

The previous prime is 7780023619. The next prime is 7780023659. The reversal of 7780023649 is 9463200877.

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 1861491025 + 5918532624 = 43145^2 + 76932^2 .

It is a cyclic number.

It is not a de Polignac number, because 7780023649 - 2⁵ = 7780023617 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 7780023599 and 7780023608.

It is not an unprimeable number, because it can be changed into a prime (7780023619) 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, 14460742 + ... + 14461279.

It is an arithmetic number, because the mean of its divisors is an integer number (1952236485).

Almost surely, 2^7780023649 is an apocalyptic number.

It is an amenable number.

7780023649 is a deficient number, since it is larger than the sum of its proper divisors (28922291).

7780023649 is a wasteful number, since it uses less digits than its factorization.

7780023649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28922290.

The product of its (nonzero) digits is 508032, while the sum is 46.

The square root of 7780023649 is about 88204.4423427755. The cubic root of 7780023649 is about 1981.4980032817.

The spelling of 7780023649 in words is "seven billion, seven hundred eighty million, twenty-three thousand, six hundred forty-nine".