780698649 has 4 divisors (see below), whose sum is σ = 1040931536. Its totient is φ = 520465764.

The previous prime is 780698641. The next prime is 780698651. The reversal of 780698649 is 946896087.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 780698649 - 2³ = 780698641 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (780698641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 130116439 + ... + 130116444.

It is an arithmetic number, because the mean of its divisors is an integer number (260232884).

Almost surely, 2^780698649 is an apocalyptic number.

It is an amenable number.

780698649 is a deficient number, since it is larger than the sum of its proper divisors (260232887).

780698649 is a wasteful number, since it uses less digits than its factorization.

780698649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 260232886.

The product of its (nonzero) digits is 5225472, while the sum is 57.

The square root of 780698649 is about 27940.9851114809. The cubic root of 780698649 is about 920.7911629307.

The spelling of 780698649 in words is "seven hundred eighty million, six hundred ninety-eight thousand, six hundred forty-nine".