21730535 has 8 divisors (see below), whose sum is σ = 26918016. Its totient is φ = 16823520.

The previous prime is 21730531. The next prime is 21730537. The reversal of 21730535 is 53503712.

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

It is not a de Polignac number, because 21730535 - 2² = 21730531 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 (21730531) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 69944 + ... + 70253.

It is an arithmetic number, because the mean of its divisors is an integer number (3364752).

Almost surely, 2^21730535 is an apocalyptic number.

21730535 is a deficient number, since it is larger than the sum of its proper divisors (5187481).

21730535 is a wasteful number, since it uses less digits than its factorization.

21730535 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 140233.

The product of its (nonzero) digits is 3150, while the sum is 26.

The square root of 21730535 is about 4661.6021923798. The cubic root of 21730535 is about 279.0552127554.

The spelling of 21730535 in words is "twenty-one million, seven hundred thirty thousand, five hundred thirty-five".