21233949 has 8 divisors (see below), whose sum is σ = 30885792. Its totient is φ = 12869040.

The previous prime is 21233939. The next prime is 21233957. The reversal of 21233949 is 94933212.

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

It is not a de Polignac number, because 21233949 - 2¹⁷ = 21102877 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33), and also a Moran number because the ratio is a prime number: 643453 = 21233949 / (2 + 1 + 2 + 3 + 3 + 9 + 4 + 9).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21233909) 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, 321694 + ... + 321759.

It is an arithmetic number, because the mean of its divisors is an integer number (3860724).

Almost surely, 2^21233949 is an apocalyptic number.

It is an amenable number.

21233949 is a deficient number, since it is larger than the sum of its proper divisors (9651843).

21233949 is a wasteful number, since it uses less digits than its factorization.

21233949 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 643467.

The product of its digits is 11664, while the sum is 33.

The square root of 21233949 is about 4608.0309243754. The cubic root of 21233949 is about 276.9131564051.

The spelling of 21233949 in words is "twenty-one million, two hundred thirty-three thousand, nine hundred forty-nine".