21155234445 has 24 divisors (see below), whose sum is σ = 36779881632. Its totient is φ = 11248696800.

The previous prime is 21155234357. The next prime is 21155234453. The reversal of 21155234445 is 54443255112.

21155234445 is a `hidden beast` number, since 21 + 1 + 552 + 3 + 44 + 45 = 666.

It is not a de Polignac number, because 21155234445 - 2¹⁴ = 21155218061 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 695251 + ... + 725040.

It is an arithmetic number, because the mean of its divisors is an integer number (1532495068).

Almost surely, 2^21155234445 is an apocalyptic number.

It is an amenable number.

21155234445 is a deficient number, since it is larger than the sum of its proper divisors (15624647187).

21155234445 is a wasteful number, since it uses less digits than its factorization.

21155234445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1420633 (or 1420630 counting only the distinct ones).

The product of its digits is 96000, while the sum is 36.

Adding to 21155234445 its reverse (54443255112), we get a palindrome (75598489557).

The spelling of 21155234445 in words is "twenty-one billion, one hundred fifty-five million, two hundred thirty-four thousand, four hundred forty-five".