21248542 has 8 divisors (see below), whose sum is σ = 36426096. Its totient is φ = 9106512.

The previous prime is 21248533. The next prime is 21248543. The reversal of 21248542 is 24584212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 21248542.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21248543) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 758863 + ... + 758890.

It is an arithmetic number, because the mean of its divisors is an integer number (4553262).

Almost surely, 2^21248542 is an apocalyptic number.

21248542 is a deficient number, since it is larger than the sum of its proper divisors (15177554).

21248542 is a wasteful number, since it uses less digits than its factorization.

21248542 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1517762.

The product of its digits is 5120, while the sum is 28.

The square root of 21248542 is about 4609.6140836300. The cubic root of 21248542 is about 276.9765779307.

The spelling of 21248542 in words is "twenty-one million, two hundred forty-eight thousand, five hundred forty-two".