20566851217402 has 24 divisors (see below), whose sum is σ = 35943042873780. Its totient is φ = 8800613821440.

The previous prime is 20566851217399. The next prime is 20566851217441. The reversal of 20566851217402 is 20471215866502.

It can be written as a sum of positive squares in 2 ways, for example, as 20435001619081 + 131849598321 = 4520509^2 + 363111^2 .

It is a Harshad number since it is a multiple of its sum of digits (49).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 163639077 + ... + 163764712.

Almost surely, 2^{20566851217402} is an apocalyptic number.

20566851217402 is a deficient number, since it is larger than the sum of its proper divisors (15376191656378).

20566851217402 is a wasteful number, since it uses less digits than its factorization.

20566851217402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 327404446 (or 327404439 counting only the distinct ones).

The product of its (nonzero) digits is 1612800, while the sum is 49.

The spelling of 20566851217402 in words is "twenty trillion, five hundred sixty-six billion, eight hundred fifty-one million, two hundred seventeen thousand, four hundred two".