21154612 has 6 divisors (see below), whose sum is σ = 37020578. Its totient is φ = 10577304.

The previous prime is 21154603. The next prime is 21154631. The reversal of 21154612 is 21645112.

It can be written as a sum of positive squares in only one way, i.e., 13734436 + 7420176 = 3706^2 + 2724^2 .

It is a congruent number.

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 as a sum of consecutive naturals, namely, 2644323 + ... + 2644330.

Almost surely, 2^21154612 is an apocalyptic number.

It is an amenable number.

21154612 is a deficient number, since it is larger than the sum of its proper divisors (15865966).

21154612 is a wasteful number, since it uses less digits than its factorization.

21154612 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5288657 (or 5288655 counting only the distinct ones).

The product of its digits is 480, while the sum is 22.

The square root of 21154612 is about 4599.4143105400. The cubic root of 21154612 is about 276.5678465159.

Adding to 21154612 its reverse (21645112), we get a palindrome (42799724).

The spelling of 21154612 in words is "twenty-one million, one hundred fifty-four thousand, six hundred twelve".