21554656212 has 48 divisors (see below), whose sum is σ = 51678573632. Its totient is φ = 6987306240.

The previous prime is 21554656187. The next prime is 21554656213. The reversal of 21554656212 is 21265645512.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21554656213) 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, 1002123 + ... + 1023405.

Almost surely, 2^21554656212 is an apocalyptic number.

It is an amenable number.

21554656212 is an abundant number, since it is smaller than the sum of its proper divisors (30123917420).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21554656212 is a wasteful number, since it uses less digits than its factorization.

21554656212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23608 (or 23606 counting only the distinct ones).

The product of its digits is 144000, while the sum is 39.

The spelling of 21554656212 in words is "twenty-one billion, five hundred fifty-four million, six hundred fifty-six thousand, two hundred twelve".