21451454 has 4 divisors (see below), whose sum is σ = 32177184. Its totient is φ = 10725726.

The previous prime is 21451439. The next prime is 21451459. The reversal of 21451454 is 45415412.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21451459) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5362862 + ... + 5362865.

It is an arithmetic number, because the mean of its divisors is an integer number (8044296).

Almost surely, 2^21451454 is an apocalyptic number.

21451454 is a deficient number, since it is larger than the sum of its proper divisors (10725730).

21451454 is a wasteful number, since it uses less digits than its factorization.

21451454 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10725729.

The product of its digits is 3200, while the sum is 26.

The square root of 21451454 is about 4631.5714395872. The cubic root of 21451454 is about 277.8554447474.

Adding to 21451454 its reverse (45415412), we get a palindrome (66866866).

The spelling of 21451454 in words is "twenty-one million, four hundred fifty-one thousand, four hundred fifty-four".