21550114243551 has 4 divisors (see below), whose sum is σ = 28733485658072. Its totient is φ = 14366742829032.

The previous prime is 21550114243531. The next prime is 21550114243571. The reversal of 21550114243551 is 15534241105512.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (21550114243531) and next prime (21550114243571).

It is not a de Polignac number, because 21550114243551 - 2¹⁹ = 21550113719263 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21550114243531) 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, 3591685707256 + ... + 3591685707261.

It is an arithmetic number, because the mean of its divisors is an integer number (7183371414518).

Almost surely, 2^{21550114243551} is an apocalyptic number.

21550114243551 is a deficient number, since it is larger than the sum of its proper divisors (7183371414521).

21550114243551 is an equidigital number, since it uses as much as digits as its factorization.

21550114243551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7183371414520.

The product of its (nonzero) digits is 120000, while the sum is 39.

The spelling of 21550114243551 in words is "twenty-one trillion, five hundred fifty billion, one hundred fourteen million, two hundred forty-three thousand, five hundred fifty-one".