21437416 has 64 divisors (see below), whose sum is σ = 53988480. Its totient is φ = 7706880.

The previous prime is 21437411. The next prime is 21437431. The reversal of 21437416 is 61473412.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21437411) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6670 + ... + 9346.

It is an arithmetic number, because the mean of its divisors is an integer number (843570).

Almost surely, 2^21437416 is an apocalyptic number.

21437416 is a gapful number since it is divisible by the number (26) 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 21437416, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26994240).

21437416 is an abundant number, since it is smaller than the sum of its proper divisors (32551064).

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

21437416 is a wasteful number, since it uses less digits than its factorization.

21437416 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2714 (or 2710 counting only the distinct ones).

The product of its digits is 4032, while the sum is 28.

The square root of 21437416 is about 4630.0557232068. The cubic root of 21437416 is about 277.7948212594.

It can be divided in two parts, 2143 and 7416, that added together give a palindrome (9559).

The spelling of 21437416 in words is "twenty-one million, four hundred thirty-seven thousand, four hundred sixteen".