7779400778464 has 24 divisors (see below), whose sum is σ = 17503651752048. Its totient is φ = 3334028904960.

The previous prime is 7779400778411. The next prime is 7779400778467. The reversal of 7779400778464 is 4648770049777.

It is a junction number, because it is equal to n+sod(n) for n = 7779400778393 and 7779400778402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7779400778467) 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, 17364733657 + ... + 17364734104.

It is an arithmetic number, because the mean of its divisors is an integer number (729318823002).

Almost surely, 2^{7779400778464} is an apocalyptic number.

It is an amenable number.

7779400778464 is an abundant number, since it is smaller than the sum of its proper divisors (9724250973584).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

7779400778464 is a wasteful number, since it uses less digits than its factorization.

7779400778464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34729467778 (or 34729467770 counting only the distinct ones).

The product of its (nonzero) digits is 464679936, while the sum is 70.

The spelling of 7779400778464 in words is "seven trillion, seven hundred seventy-nine billion, four hundred million, seven hundred seventy-eight thousand, four hundred sixty-four".