21354420 has 48 divisors (see below), whose sum is σ = 60213888. Its totient is φ = 5654400.

The previous prime is 21354413. The next prime is 21354433. The reversal of 21354420 is 2445312.

It is a super-2 number, since 2×21354420² = 912022507072800, which contains 22 as substring.

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, 7882 + ... + 10238.

It is an arithmetic number, because the mean of its divisors is an integer number (1254456).

Almost surely, 2^21354420 is an apocalyptic number.

21354420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21354420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30106944).

21354420 is an abundant number, since it is smaller than the sum of its proper divisors (38859468).

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

21354420 is a wasteful number, since it uses less digits than its factorization.

21354420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2520 (or 2518 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 21.

The square root of 21354420 is about 4621.0842883462. The cubic root of 21354420 is about 277.4358588872.

Adding to 21354420 its reverse (2445312), we get a palindrome (23799732).

It can be divided in two parts, 2135 and 4420, that added together give a triangular number (6555 = T₁₁₄).

The spelling of 21354420 in words is "twenty-one million, three hundred fifty-four thousand, four hundred twenty".