21488957 has 8 divisors (see below), whose sum is σ = 24685056. Its totient is φ = 18324432.

The previous prime is 21488953. The next prime is 21488963. The reversal of 21488957 is 75988412.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21488957 - 2² = 21488953 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21488953) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6413 + ... + 9170.

It is an arithmetic number, because the mean of its divisors is an integer number (3085632).

Almost surely, 2^21488957 is an apocalyptic number.

It is an amenable number.

21488957 is a deficient number, since it is larger than the sum of its proper divisors (3196099).

21488957 is a wasteful number, since it uses less digits than its factorization.

21488957 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15787.

The product of its digits is 161280, while the sum is 44.

The square root of 21488957 is about 4635.6182974874. The cubic root of 21488957 is about 278.0172728774.

The spelling of 21488957 in words is "twenty-one million, four hundred eighty-eight thousand, nine hundred fifty-seven".