21136455 has 48 divisors (see below), whose sum is σ = 39312000. Its totient is φ = 10473408.

The previous prime is 21136441. The next prime is 21136463. The reversal of 21136455 is 55463112.

21136455 is a `hidden beast` number, since 2 + 1 + 13 + 645 + 5 = 666.

It is not a de Polignac number, because 21136455 - 2¹⁰ = 21135431 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 50236 + ... + 50654.

It is an arithmetic number, because the mean of its divisors is an integer number (819000).

Almost surely, 2^21136455 is an apocalyptic number.

21136455 is a deficient number, since it is larger than the sum of its proper divisors (18175545).

21136455 is a wasteful number, since it uses less digits than its factorization.

21136455 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 508 (or 505 counting only the distinct ones).

The product of its digits is 3600, while the sum is 27.

The square root of 21136455 is about 4597.4400485488. The cubic root of 21136455 is about 276.4886978214.

Adding to 21136455 its reverse (55463112), we get a palindrome (76599567).

The spelling of 21136455 in words is "twenty-one million, one hundred thirty-six thousand, four hundred fifty-five".