21003154 has 8 divisors (see below), whose sum is σ = 32021388. Its totient is φ = 10329360.

The previous prime is 21003139. The next prime is 21003173. The reversal of 21003154 is 45130012.

It can be written as a sum of positive squares in 2 ways, for example, as 16281225 + 4721929 = 4035^2 + 2173^2 .

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

It is a super-2 number, since 2×21003154² = 882264955895432, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 85957 + ... + 86200.

Almost surely, 2^21003154 is an apocalyptic number.

21003154 is a deficient number, since it is larger than the sum of its proper divisors (11018234).

21003154 is a wasteful number, since it uses less digits than its factorization.

21003154 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 172220.

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 21003154 is about 4582.9198116485. The cubic root of 21003154 is about 275.9062290845.

Adding to 21003154 its reverse (45130012), we get a palindrome (66133166).

The spelling of 21003154 in words is "twenty-one million, three thousand, one hundred fifty-four".