21148497 has 24 divisors (see below), whose sum is σ = 32159400. Its totient is φ = 13374720.

The previous prime is 21148481. The next prime is 21148499. The reversal of 21148497 is 79484112.

21148497 is a `hidden beast` number, since 21 + 148 + 497 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 1354896 + 19793601 = 1164^2 + 4449^2 .

It is not a de Polignac number, because 21148497 - 2⁴ = 21148481 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21148499) 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 23 ways as a sum of consecutive naturals, for example, 12879 + ... + 14427.

It is an arithmetic number, because the mean of its divisors is an integer number (1339975).

Almost surely, 2^21148497 is an apocalyptic number.

It is an amenable number.

21148497 is a deficient number, since it is larger than the sum of its proper divisors (11010903).

21148497 is a wasteful number, since it uses less digits than its factorization.

21148497 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1633 (or 1630 counting only the distinct ones).

The product of its digits is 16128, while the sum is 36.

The square root of 21148497 is about 4598.7495039413. The cubic root of 21148497 is about 276.5411955053.

The spelling of 21148497 in words is "twenty-one million, one hundred forty-eight thousand, four hundred ninety-seven".