21150554 has 8 divisors (see below), whose sum is σ = 31920960. Its totient is φ = 10510236.

The previous prime is 21150523. The next prime is 21150607. The reversal of 21150554 is 45505112.

It is a happy number.

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

It is an unprimeable number.

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, 32114 + ... + 32765.

It is an arithmetic number, because the mean of its divisors is an integer number (3990120).

Almost surely, 2^21150554 is an apocalyptic number.

21150554 is a deficient number, since it is larger than the sum of its proper divisors (10770406).

21150554 is a wasteful number, since it uses less digits than its factorization.

21150554 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65044.

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

The square root of 21150554 is about 4598.9731462578. The cubic root of 21150554 is about 276.5501611038.

Adding to 21150554 its reverse (45505112), we get a palindrome (66655666).

The spelling of 21150554 in words is "twenty-one million, one hundred fifty thousand, five hundred fifty-four".