21162457 has 4 divisors (see below), whose sum is σ = 21237520. Its totient is φ = 21087396.

The previous prime is 21162439. The next prime is 21162469. The reversal of 21162457 is 75426112.

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 21162457 - 2⁷ = 21162329 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21162487) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 37107 + ... + 37672.

It is an arithmetic number, because the mean of its divisors is an integer number (5309380).

Almost surely, 2^21162457 is an apocalyptic number.

It is an amenable number.

21162457 is a deficient number, since it is larger than the sum of its proper divisors (75063).

21162457 is an equidigital number, since it uses as much as digits as its factorization.

21162457 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75062.

The product of its digits is 3360, while the sum is 28.

The square root of 21162457 is about 4600.2670574653. The cubic root of 21162457 is about 276.6020298673.

Adding to 21162457 its reverse (75426112), we get a palindrome (96588569).

The spelling of 21162457 in words is "twenty-one million, one hundred sixty-two thousand, four hundred fifty-seven".