21651888551416 has 16 divisors (see below), whose sum is σ = 40684223141640. Its totient is φ = 10802762380320.

The previous prime is 21651888551383. The next prime is 21651888551417. The reversal of 21651888551416 is 61415588815612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21651888551417) 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, 2897732955 + ... + 2897740426.

Almost surely, 2^{21651888551416} is an apocalyptic number.

It is an amenable number.

21651888551416 is a deficient number, since it is larger than the sum of its proper divisors (19032334590224).

21651888551416 is a wasteful number, since it uses less digits than its factorization.

21651888551416 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5795473854 (or 5795473850 counting only the distinct ones).

The product of its digits is 18432000, while the sum is 61.

The spelling of 21651888551416 in words is "twenty-one trillion, six hundred fifty-one billion, eight hundred eighty-eight million, five hundred fifty-one thousand, four hundred sixteen".