21733531 has 8 divisors (see below), whose sum is σ = 23104224. Its totient is φ = 20373120.

The previous prime is 21733513. The next prime is 21733561. The reversal of 21733531 is 13533712.

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

It is a cyclic number.

It is not a de Polignac number, because 21733531 - 2¹⁷ = 21602459 is a prime.

It is a super-2 number, since 2×21733531² = 944692739455922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21733496 and 21733505.

It is not an unprimeable number, because it can be changed into a prime (21733561) 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, 2041 + ... + 6901.

It is an arithmetic number, because the mean of its divisors is an integer number (2888028).

Almost surely, 2^21733531 is an apocalyptic number.

21733531 is a deficient number, since it is larger than the sum of its proper divisors (1370693).

21733531 is a wasteful number, since it uses less digits than its factorization.

21733531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5141.

The product of its digits is 1890, while the sum is 25.

The square root of 21733531 is about 4661.9235300464. The cubic root of 21733531 is about 279.0680366612.

The spelling of 21733531 in words is "twenty-one million, seven hundred thirty-three thousand, five hundred thirty-one".