21454120 has 16 divisors (see below), whose sum is σ = 48271860. Its totient is φ = 8581632.

The previous prime is 21454099. The next prime is 21454123. The reversal of 21454120 is 2145412.

It can be written as a sum of positive squares in 2 ways, for example, as 19695844 + 1758276 = 4438^2 + 1326^2 .

It is not an unprimeable number, because it can be changed into a prime (21454123) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 268137 + ... + 268216.

Almost surely, 2^21454120 is an apocalyptic number.

21454120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21454120 is an abundant number, since it is smaller than the sum of its proper divisors (26817740).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21454120 is a wasteful number, since it uses less digits than its factorization.

21454120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 536364 (or 536360 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 19.

The square root of 21454120 is about 4631.8592379303. The cubic root of 21454120 is about 277.8669549529.

Adding to 21454120 its reverse (2145412), we get a palindrome (23599532).

The spelling of 21454120 in words is "twenty-one million, four hundred fifty-four thousand, one hundred twenty".