21154544 has 10 divisors (see below), whose sum is σ = 40986960. Its totient is φ = 10577264.

The previous prime is 21154519. The next prime is 21154547. The reversal of 21154544 is 44545112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21154547) 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 as a sum of consecutive naturals, namely, 661064 + ... + 661095.

It is an arithmetic number, because the mean of its divisors is an integer number (4098696).

Almost surely, 2^21154544 is an apocalyptic number.

It is an amenable number.

21154544 is a deficient number, since it is larger than the sum of its proper divisors (19832416).

21154544 is a wasteful number, since it uses less digits than its factorization.

21154544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1322167 (or 1322161 counting only the distinct ones).

The product of its digits is 3200, while the sum is 26.

The square root of 21154544 is about 4599.4069182885. The cubic root of 21154544 is about 276.5675501796.

Adding to 21154544 its reverse (44545112), we get a palindrome (65699656).

The spelling of 21154544 in words is "twenty-one million, one hundred fifty-four thousand, five hundred forty-four".