21151033 has 4 divisors (see below), whose sum is σ = 21160528. Its totient is φ = 21141540.

The previous prime is 21151027. The next prime is 21151049. The reversal of 21151033 is 33015112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21151033 - 2¹⁷ = 21019961 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21150998 and 21151016.

It is not an unprimeable number, because it can be changed into a prime (21151433) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 610 + ... + 6532.

It is an arithmetic number, because the mean of its divisors is an integer number (5290132).

Almost surely, 2^21151033 is an apocalyptic number.

It is an amenable number.

21151033 is a deficient number, since it is larger than the sum of its proper divisors (9495).

21151033 is an equidigital number, since it uses as much as digits as its factorization.

21151033 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9494.

The product of its (nonzero) digits is 90, while the sum is 16.

The square root of 21151033 is about 4599.0252228054. The cubic root of 21151033 is about 276.5522487800.

Adding to 21151033 its reverse (33015112), we get a palindrome (54166145).

The spelling of 21151033 in words is "twenty-one million, one hundred fifty-one thousand, thirty-three".