21377748 has 48 divisors (see below), whose sum is σ = 57405824. Its totient is φ = 6065280.

The previous prime is 21377731. The next prime is 21377767. The reversal of 21377748 is 84777312.

It is a congruent number.

It is an unprimeable 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 15 ways as a sum of consecutive naturals, for example, 12378 + ... + 13998.

Almost surely, 2^21377748 is an apocalyptic number.

21377748 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 21377748, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28702912).

21377748 is an abundant number, since it is smaller than the sum of its proper divisors (36028076).

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

21377748 is a wasteful number, since it uses less digits than its factorization.

21377748 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1792 (or 1790 counting only the distinct ones).

The product of its digits is 65856, while the sum is 39.

The square root of 21377748 is about 4623.6076823191. The cubic root of 21377748 is about 277.5368476352.

The spelling of 21377748 in words is "twenty-one million, three hundred seventy-seven thousand, seven hundred forty-eight".