21234455 has 16 divisors (see below), whose sum is σ = 27933984. Its totient is φ = 15367680.

The previous prime is 21234443. The next prime is 21234461. The reversal of 21234455 is 55443212.

It is a happy number.

It is not a de Polignac number, because 21234455 - 2⁶ = 21234391 is a prime.

It is a Duffinian number.

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, 11987 + ... + 13643.

It is an arithmetic number, because the mean of its divisors is an integer number (1745874).

Almost surely, 2^21234455 is an apocalyptic number.

21234455 is a deficient number, since it is larger than the sum of its proper divisors (6699529).

21234455 is a wasteful number, since it uses less digits than its factorization.

21234455 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1906.

The product of its digits is 4800, while the sum is 26.

The square root of 21234455 is about 4608.0858281937. The cubic root of 21234455 is about 276.9153559793.

Adding to 21234455 its reverse (55443212), we get a palindrome (76677667).

The spelling of 21234455 in words is "twenty-one million, two hundred thirty-four thousand, four hundred fifty-five".