21488742 has 24 divisors (see below), whose sum is σ = 50792040. Its totient is φ = 6511680.

The previous prime is 21488741. The next prime is 21488759. The reversal of 21488742 is 24788412.

It is a junction number, because it is equal to n+sod(n) for n = 21488697 and 21488706.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21488741) 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 11 ways as a sum of consecutive naturals, for example, 54067 + ... + 54462.

It is an arithmetic number, because the mean of its divisors is an integer number (2116335).

Almost surely, 2^21488742 is an apocalyptic number.

21488742 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21488742 is an abundant number, since it is smaller than the sum of its proper divisors (29303298).

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

21488742 is a wasteful number, since it uses less digits than its factorization.

21488742 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 108548 (or 108545 counting only the distinct ones).

The product of its digits is 28672, while the sum is 36.

The square root of 21488742 is about 4635.5951074269. The cubic root of 21488742 is about 278.0163456738.

The spelling of 21488742 in words is "twenty-one million, four hundred eighty-eight thousand, seven hundred forty-two".