21154201 has 4 divisors (see below), whose sum is σ = 22267600. Its totient is φ = 20040804.

The previous prime is 21154193. The next prime is 21154207. The reversal of 21154201 is 10245112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21154201 - 2³ = 21154193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21154207) 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 3 ways as a sum of consecutive naturals, for example, 556671 + ... + 556708.

It is an arithmetic number, because the mean of its divisors is an integer number (5566900).

Almost surely, 2^21154201 is an apocalyptic number.

It is an amenable number.

21154201 is a deficient number, since it is larger than the sum of its proper divisors (1113399).

21154201 is a wasteful number, since it uses less digits than its factorization.

21154201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1113398.

The product of its (nonzero) digits is 80, while the sum is 16.

The square root of 21154201 is about 4599.3696307211. The cubic root of 21154201 is about 276.5660554152.

Adding to 21154201 its reverse (10245112), we get a palindrome (31399313).

The spelling of 21154201 in words is "twenty-one million, one hundred fifty-four thousand, two hundred one".