21292733 has 24 divisors (see below), whose sum is σ = 27936384. Its totient is φ = 15855840.

The previous prime is 21292729. The next prime is 21292751. The reversal of 21292733 is 33729212.

It is not a de Polignac number, because 21292733 - 2² = 21292729 is a prime.

It is a Smith number, since the sum of its digits (29) coincides with the sum of the digits of its prime factors.

Its product of digits (4536) is a multiple of the sum of its prime divisors (1134).

It is a junction number, because it is equal to n+sod(n) for n = 21292696 and 21292705.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21292433) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 18935 + ... + 20027.

It is an arithmetic number, because the mean of its divisors is an integer number (1164016).

Almost surely, 2^21292733 is an apocalyptic number.

21292733 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

21292733 is a deficient number, since it is larger than the sum of its proper divisors (6643651).

21292733 is a wasteful number, since it uses less digits than its factorization.

21292733 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1145 (or 1134 counting only the distinct ones).

The product of its digits is 4536, while the sum is 29.

The square root of 21292733 is about 4614.4049453857. The cubic root of 21292733 is about 277.1684561402.

The spelling of 21292733 in words is "twenty-one million, two hundred ninety-two thousand, seven hundred thirty-three".