21254556445 has 16 divisors (see below), whose sum is σ = 25643825280. Its totient is φ = 16911518400.

The previous prime is 21254556439. The next prime is 21254556457. The reversal of 21254556445 is 54465545212.

It is a happy number.

It is not a de Polignac number, because 21254556445 - 2³ = 21254556437 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1754760 + ... + 1766830.

It is an arithmetic number, because the mean of its divisors is an integer number (1602739080).

Almost surely, 2^21254556445 is an apocalyptic number.

It is an amenable number.

21254556445 is a deficient number, since it is larger than the sum of its proper divisors (4389268835).

21254556445 is a wasteful number, since it uses less digits than its factorization.

21254556445 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13956.

The product of its digits is 960000, while the sum is 43.

The spelling of 21254556445 in words is "twenty-one billion, two hundred fifty-four million, five hundred fifty-six thousand, four hundred forty-five".