21423948 has 96 divisors (see below), whose sum is σ = 64275456. Its totient is φ = 5398272.

The previous prime is 21423917. The next prime is 21423959. The reversal of 21423948 is 84932412.

It is a super-3 number, since 3×21423948³ (a number of 23 digits) contains 333 as substring.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 24690 + ... + 25542.

It is an arithmetic number, because the mean of its divisors is an integer number (669536).

Almost surely, 2^21423948 is an apocalyptic number.

21423948 is a gapful number since it is divisible by the number (28) 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 21423948, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32137728).

21423948 is an abundant number, since it is smaller than the sum of its proper divisors (42851508).

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

21423948 is a wasteful number, since it uses less digits than its factorization.

21423948 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 903 (or 901 counting only the distinct ones).

The product of its digits is 13824, while the sum is 33.

The square root of 21423948 is about 4628.6010845611. The cubic root of 21423948 is about 277.7366344515.

The spelling of 21423948 in words is "twenty-one million, four hundred twenty-three thousand, nine hundred forty-eight".