21488451 has 16 divisors (see below), whose sum is σ = 29205120. Its totient is φ = 14051520.

The previous prime is 21488431. The next prime is 21488477. The reversal of 21488451 is 15488412.

It is not a de Polignac number, because 21488451 - 2¹¹ = 21486403 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21488431) 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 15 ways as a sum of consecutive naturals, for example, 52335 + ... + 52743.

It is an arithmetic number, because the mean of its divisors is an integer number (1825320).

Almost surely, 2^21488451 is an apocalyptic number.

21488451 is a deficient number, since it is larger than the sum of its proper divisors (7716669).

21488451 is a wasteful number, since it uses less digits than its factorization.

21488451 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 706.

The product of its digits is 10240, while the sum is 33.

The square root of 21488451 is about 4635.5637197648. The cubic root of 21488451 is about 278.0150907047.

The spelling of 21488451 in words is "twenty-one million, four hundred eighty-eight thousand, four hundred fifty-one".