21154245 has 64 divisors (see below), whose sum is σ = 40943616. Its totient is φ = 9123840.

The previous prime is 21154207. The next prime is 21154283. The reversal of 21154245 is 54245112.

It is an interprime number because it is at equal distance from previous prime (21154207) and next prime (21154283).

It is not a de Polignac number, because 21154245 - 2¹³ = 21146053 is a prime.

It is a Curzon number.

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 in 63 ways as a sum of consecutive naturals, for example, 218037 + ... + 218133.

It is an arithmetic number, because the mean of its divisors is an integer number (639744).

Almost surely, 2^21154245 is an apocalyptic number.

It is an amenable number.

21154245 is a deficient number, since it is larger than the sum of its proper divisors (19789371).

21154245 is a wasteful number, since it uses less digits than its factorization.

21154245 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 210.

The product of its digits is 1600, while the sum is 24.

The square root of 21154245 is about 4599.3744139828. The cubic root of 21154245 is about 276.5662471643.

Adding to 21154245 its reverse (54245112), we get a palindrome (75399357).

The spelling of 21154245 in words is "twenty-one million, one hundred fifty-four thousand, two hundred forty-five".