21754501 has 4 divisors (see below), whose sum is σ = 21763852. Its totient is φ = 21745152.

The previous prime is 21754489. The next prime is 21754507. The reversal of 21754501 is 10545712.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 17023876 + 4730625 = 4126^2 + 2175^2 .

It is a cyclic number.

It is not a de Polignac number, because 21754501 - 2⁹ = 21753989 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21754507) 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 3 ways as a sum of consecutive naturals, for example, 1861 + ... + 6853.

It is an arithmetic number, because the mean of its divisors is an integer number (5440963).

Almost surely, 2^21754501 is an apocalyptic number.

It is an amenable number.

21754501 is a deficient number, since it is larger than the sum of its proper divisors (9351).

21754501 is an equidigital number, since it uses as much as digits as its factorization.

21754501 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9350.

The product of its (nonzero) digits is 1400, while the sum is 25.

The square root of 21754501 is about 4664.1720594335. The cubic root of 21754501 is about 279.1577624644.

The spelling of 21754501 in words is "twenty-one million, seven hundred fifty-four thousand, five hundred one".