21233955 has 16 divisors (see below), whose sum is σ = 34122240. Its totient is φ = 11275488.

The previous prime is 21233939. The next prime is 21233957. The reversal of 21233955 is 55933212.

It is not a de Polignac number, because 21233955 - 2⁴ = 21233939 is a prime.

It is a super-4 number, since 4×21233955⁴ (a number of 30 digits) contains 4444 as substring.

It is not an unprimeable number, because it can be changed into a prime (21233957) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 624 + ... + 6546.

It is an arithmetic number, because the mean of its divisors is an integer number (2132640).

Almost surely, 2^21233955 is an apocalyptic number.

21233955 is a deficient number, since it is larger than the sum of its proper divisors (12888285).

21233955 is a wasteful number, since it uses less digits than its factorization.

21233955 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6170.

The product of its digits is 8100, while the sum is 30.

The square root of 21233955 is about 4608.0315754127. The cubic root of 21233955 is about 276.9131824872.

The spelling of 21233955 in words is "twenty-one million, two hundred thirty-three thousand, nine hundred fifty-five".