21464520 has 256 divisors, whose sum is σ = 84602880. Its totient is φ = 4224000.

The previous prime is 21464503. The next prime is 21464539. The reversal of 21464520 is 2546412.

21464520 = T₁ + T₂ + ... + T₅₀₄.

21464520 is a nontrivial binomial coefficient, being equal to C(506, 3).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is an unprimeable number.

It is the 504-th tetrahedral number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 212470 + ... + 212570.

It is an arithmetic number, because the mean of its divisors is an integer number (330480).

Almost surely, 2^21464520 is an apocalyptic number.

21464520 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 21464520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42301440).

21464520 is an abundant number, since it is smaller than the sum of its proper divisors (63138360).

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

21464520 is a wasteful number, since it uses less digits than its factorization.

21464520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 156 (or 152 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 24.

The square root of 21464520 is about 4632.9817612419. The cubic root of 21464520 is about 277.9118468665.

It can be divided in two parts, 2146 and 4520, that added together give a palindrome (6666).

The spelling of 21464520 in words is "twenty-one million, four hundred sixty-four thousand, five hundred twenty".