21699748 has 36 divisors (see below), whose sum is σ = 46507440. Its totient is φ = 8808912.

The previous prime is 21699739. The next prime is 21699751. The reversal of 21699748 is 84799612.

It is a junction number, because it is equal to n+sod(n) for n = 21699698 and 21699707.

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 11 ways as a sum of consecutive naturals, for example, 811 + ... + 6637.

Almost surely, 2^21699748 is an apocalyptic number.

21699748 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 21699748, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23253720).

21699748 is an abundant number, since it is smaller than the sum of its proper divisors (24807692).

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

21699748 is a wasteful number, since it uses less digits than its factorization.

21699748 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5864 (or 5855 counting only the distinct ones).

The product of its digits is 217728, while the sum is 46.

The square root of 21699748 is about 4658.2988311185. The cubic root of 21699748 is about 278.9233655138.

The spelling of 21699748 in words is "twenty-one million, six hundred ninety-nine thousand, seven hundred forty-eight".