21238955 has 8 divisors (see below), whose sum is σ = 25967952. Its totient is φ = 16670368.

The previous prime is 21238949. The next prime is 21238963. The reversal of 21238955 is 55983212.

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 21238955 - 2⁴ = 21238939 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39809 + ... + 40338.

It is an arithmetic number, because the mean of its divisors is an integer number (3245994).

Almost surely, 2^21238955 is an apocalyptic number.

21238955 is a deficient number, since it is larger than the sum of its proper divisors (4728997).

21238955 is an equidigital number, since it uses as much as digits as its factorization.

21238955 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80205.

The product of its digits is 21600, while the sum is 35.

The square root of 21238955 is about 4608.5740744833. The cubic root of 21238955 is about 276.9349158736.

The spelling of 21238955 in words is "twenty-one million, two hundred thirty-eight thousand, nine hundred fifty-five".