21029693 has 4 divisors (see below), whose sum is σ = 21090300. Its totient is φ = 20969088.

The previous prime is 21029683. The next prime is 21029717. The reversal of 21029693 is 39692012.

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 16176484 + 4853209 = 4022^2 + 2203^2 .

It is a cyclic number.

It is not a de Polignac number, because 21029693 - 2⁴ = 21029677 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 (21029683) 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, 29780 + ... + 30477.

It is an arithmetic number, because the mean of its divisors is an integer number (5272575).

Almost surely, 2^21029693 is an apocalyptic number.

It is an amenable number.

21029693 is a deficient number, since it is larger than the sum of its proper divisors (60607).

21029693 is an equidigital number, since it uses as much as digits as its factorization.

21029693 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60606.

The product of its (nonzero) digits is 5832, while the sum is 32.

The square root of 21029693 is about 4585.8143224514. The cubic root of 21029693 is about 276.0223893130.

The spelling of 21029693 in words is "twenty-one million, twenty-nine thousand, six hundred ninety-three".