21154633 has 6 divisors (see below), whose sum is σ = 21418586. Its totient is φ = 20891712.

The previous prime is 21154631. The next prime is 21154669. The reversal of 21154633 is 33645112.

It can be written as a sum of positive squares in only one way, i.e., 17665209 + 3489424 = 4203^2 + 1868^2 .

It is not a de Polignac number, because 21154633 - 2¹ = 21154631 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21154598 and 21154607.

It is not an unprimeable number, because it can be changed into a prime (21154631) by changing a digit.

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 5 ways as a sum of consecutive naturals, for example, 45066 + ... + 45532.

Almost surely, 2^21154633 is an apocalyptic number.

It is an amenable number.

21154633 is a deficient number, since it is larger than the sum of its proper divisors (263953).

21154633 is an frugal number, since it uses more digits than its factorization.

21154633 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1031 (or 564 counting only the distinct ones).

The product of its digits is 2160, while the sum is 25.

The square root of 21154633 is about 4599.4165934388. The cubic root of 21154633 is about 276.5679380313.

Adding to 21154633 its reverse (33645112), we get a palindrome (54799745).

The spelling of 21154633 in words is "twenty-one million, one hundred fifty-four thousand, six hundred thirty-three".