21416420 has 24 divisors (see below), whose sum is σ = 47342400. Its totient is φ = 8115552.

The previous prime is 21416411. The next prime is 21416431. The reversal of 21416420 is 2461412.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 21416392 and 21416401.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27800 + ... + 28559.

It is an arithmetic number, because the mean of its divisors is an integer number (1972600).

Almost surely, 2^21416420 is an apocalyptic number.

21416420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21416420 is an abundant number, since it is smaller than the sum of its proper divisors (25925980).

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

21416420 is a wasteful number, since it uses less digits than its factorization.

21416420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56387 (or 56385 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 20.

The square root of 21416420 is about 4627.7878084458. The cubic root of 21416420 is about 277.7041000446.

Adding to 21416420 its reverse (2461412), we get a palindrome (23877832).

The spelling of 21416420 in words is "twenty-one million, four hundred sixteen thousand, four hundred twenty".