21748011 has 4 divisors (see below), whose sum is σ = 28997352. Its totient is φ = 14498672.

The previous prime is 21748009. The next prime is 21748033. The reversal of 21748011 is 11084712.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21748011 - 2¹ = 21748009 is a prime.

It is a super-2 number, since 2×21748011² = 945951964912242, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21748061) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3624666 + ... + 3624671.

It is an arithmetic number, because the mean of its divisors is an integer number (7249338).

Almost surely, 2^21748011 is an apocalyptic number.

21748011 is a deficient number, since it is larger than the sum of its proper divisors (7249341).

21748011 is an equidigital number, since it uses as much as digits as its factorization.

21748011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7249340.

The product of its (nonzero) digits is 448, while the sum is 24.

The square root of 21748011 is about 4663.4762784858. The cubic root of 21748011 is about 279.1299994118.

The spelling of 21748011 in words is "twenty-one million, seven hundred forty-eight thousand, eleven".