15781777320417 has 8 divisors (see below), whose sum is σ = 21531727197024. Its totient is φ = 10276506162048.

The previous prime is 15781777320389. The next prime is 15781777320427. The reversal of 15781777320417 is 71402377718751.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 15781777320417 - 2²⁴ = 15781760543201 is a prime.

It is not an unprimeable number, because it can be changed into a prime (15781777320427) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 61169679408 + ... + 61169679665.

It is an arithmetic number, because the mean of its divisors is an integer number (2691465899628).

Almost surely, 2^{15781777320417} is an apocalyptic number.

It is an amenable number.

15781777320417 is a deficient number, since it is larger than the sum of its proper divisors (5749949876607).

15781777320417 is a wasteful number, since it uses less digits than its factorization.

15781777320417 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 122339359119.

The product of its (nonzero) digits is 16134720, while the sum is 60.

The spelling of 15781777320417 in words is "fifteen trillion, seven hundred eighty-one billion, seven hundred seventy-seven million, three hundred twenty thousand, four hundred seventeen".