21754693 has 4 divisors (see below), whose sum is σ = 21970188. Its totient is φ = 21539200.

The previous prime is 21754687. The next prime is 21754697. The reversal of 21754693 is 39645712.

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

It can be written as a sum of positive squares in 2 ways, for example, as 21141604 + 613089 = 4598^2 + 783^2 .

It is a cyclic number.

It is not a de Polignac number, because 21754693 - 2¹⁷ = 21623621 is a prime.

It is a Duffinian number.

It is a plaindrome in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21754697) 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, 107596 + ... + 107797.

It is an arithmetic number, because the mean of its divisors is an integer number (5492547).

Almost surely, 2^21754693 is an apocalyptic number.

It is an amenable number.

21754693 is a deficient number, since it is larger than the sum of its proper divisors (215495).

21754693 is a wasteful number, since it uses less digits than its factorization.

21754693 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 215494.

The product of its digits is 45360, while the sum is 37.

The square root of 21754693 is about 4664.1926418192. The cubic root of 21754693 is about 279.1585837218.

The spelling of 21754693 in words is "twenty-one million, seven hundred fifty-four thousand, six hundred ninety-three".