20777455661216 has 12 divisors (see below), whose sum is σ = 40905615833082. Its totient is φ = 10388727830592.

The previous prime is 20777455661197. The next prime is 20777455661257. The reversal of 20777455661216 is 61216655477702.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 18833829321616 + 1943626339600 = 4339796^2 + 1394140^2 .

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 324647744675 + ... + 324647744738.

Almost surely, 2^{20777455661216} is an apocalyptic number.

It is an amenable number.

20777455661216 is a deficient number, since it is larger than the sum of its proper divisors (20128160171866).

20777455661216 is an equidigital number, since it uses as much as digits as its factorization.

20777455661216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 649295489423 (or 649295489415 counting only the distinct ones).

The product of its (nonzero) digits is 29635200, while the sum is 59.

The spelling of 20777455661216 in words is "twenty trillion, seven hundred seventy-seven billion, four hundred fifty-five million, six hundred sixty-one thousand, two hundred sixteen".