21224554551 has 16 divisors (see below), whose sum is σ = 31516420320. Its totient is φ = 14117016960.

The previous prime is 21224554517. The next prime is 21224554573. The reversal of 21224554551 is 15545542212.

21224554551 is a `hidden beast` number, since 2 + 1 + 22 + 45 + 545 + 51 = 666.

It is not a de Polignac number, because 21224554551 - 2¹⁹ = 21224030263 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21224554511) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 896040 + ... + 919421.

It is an arithmetic number, because the mean of its divisors is an integer number (1969776270).

Almost surely, 2^21224554551 is an apocalyptic number.

21224554551 is a deficient number, since it is larger than the sum of its proper divisors (10291865769).

21224554551 is a wasteful number, since it uses less digits than its factorization.

21224554551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1815903 (or 1815897 counting only the distinct ones).

The product of its digits is 80000, while the sum is 36.

The spelling of 21224554551 in words is "twenty-one billion, two hundred twenty-four million, five hundred fifty-four thousand, five hundred fifty-one".