21150455 has 8 divisors (see below), whose sum is σ = 26484192. Its totient is φ = 16184608.

The previous prime is 21150443. The next prime is 21150487. The reversal of 21150455 is 55405112.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21150455 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21150455.

It is a congruent 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, 91844 + ... + 92073.

It is an arithmetic number, because the mean of its divisors is an integer number (3310524).

Almost surely, 2^21150455 is an apocalyptic number.

21150455 is a deficient number, since it is larger than the sum of its proper divisors (5333737).

21150455 is a wasteful number, since it uses less digits than its factorization.

21150455 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 183945.

The product of its (nonzero) digits is 1000, while the sum is 23.

The square root of 21150455 is about 4598.9623829729. The cubic root of 21150455 is about 276.5497296177.

Adding to 21150455 its reverse (55405112), we get a palindrome (76555567).

The spelling of 21150455 in words is "twenty-one million, one hundred fifty thousand, four hundred fifty-five".