7779400778465 has 48 divisors (see below), whose sum is σ = 10286766201600. Its totient is φ = 5631750660096.

The previous prime is 7779400778411. The next prime is 7779400778467. The reversal of 7779400778465 is 5648770049777.

It is a de Polignac number, because none of the positive numbers 2^k-7779400778465 is a prime.

It is not an unprimeable number, because it can be changed into a prime (7779400778467) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 36025697 + ... + 36240993.

It is an arithmetic number, because the mean of its divisors is an integer number (214307629200).

Almost surely, 2^{7779400778465} is an apocalyptic number.

It is an amenable number.

7779400778465 is a deficient number, since it is larger than the sum of its proper divisors (2507365423135).

7779400778465 is a wasteful number, since it uses less digits than its factorization.

7779400778465 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 216086 (or 216063 counting only the distinct ones).

The product of its (nonzero) digits is 580849920, while the sum is 71.

The spelling of 7779400778465 in words is "seven trillion, seven hundred seventy-nine billion, four hundred million, seven hundred seventy-eight thousand, four hundred sixty-five".