21423416 has 32 divisors (see below), whose sum is σ = 46208640. Its totient is φ = 9121248.

The previous prime is 21423403. The next prime is 21423421. The reversal of 21423416 is 61432412.

It is a junction number, because it is equal to n+sod(n) for n = 21423391 and 21423400.

It is a congruent number.

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, 7955 + ... + 10301.

It is an arithmetic number, because the mean of its divisors is an integer number (1444020).

Almost surely, 2^21423416 is an apocalyptic number.

It is an amenable number.

21423416 is an abundant number, since it is smaller than the sum of its proper divisors (24785224).

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

21423416 is a wasteful number, since it uses less digits than its factorization.

21423416 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2523 (or 2519 counting only the distinct ones).

The product of its digits is 1152, while the sum is 23.

The square root of 21423416 is about 4628.5436154367. The cubic root of 21423416 is about 277.7343355115.

Adding to 21423416 its reverse (61432412), we get a palindrome (82855828).

The spelling of 21423416 in words is "twenty-one million, four hundred twenty-three thousand, four hundred sixteen".