21452455 has 4 divisors (see below), whose sum is σ = 25742952. Its totient is φ = 17161960.

The previous prime is 21452443. The next prime is 21452461. The reversal of 21452455 is 55425412.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 21452455 - 2¹³ = 21444263 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 3 ways as a sum of consecutive naturals, for example, 2145241 + ... + 2145250.

It is an arithmetic number, because the mean of its divisors is an integer number (6435738).

Almost surely, 2^21452455 is an apocalyptic number.

21452455 is a deficient number, since it is larger than the sum of its proper divisors (4290497).

21452455 is an equidigital number, since it uses as much as digits as its factorization.

21452455 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4290496.

The product of its digits is 8000, while the sum is 28.

The square root of 21452455 is about 4631.6795010018. The cubic root of 21452455 is about 277.8597665830.

Adding to 21452455 its reverse (55425412), we get a palindrome (76877867).

The spelling of 21452455 in words is "twenty-one million, four hundred fifty-two thousand, four hundred fifty-five".