21488147 has 4 divisors (see below), whose sum is σ = 21498840. Its totient is φ = 21477456.

The previous prime is 21488143. The next prime is 21488171. The reversal of 21488147 is 74188412.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21488147 - 2² = 21488143 is a prime.

It is a super-2 number, since 2×21488147² = 923480922987218, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21488143) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1322 + ... + 6687.

It is an arithmetic number, because the mean of its divisors is an integer number (5374710).

Almost surely, 2^21488147 is an apocalyptic number.

21488147 is a deficient number, since it is larger than the sum of its proper divisors (10693).

21488147 is an equidigital number, since it uses as much as digits as its factorization.

21488147 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10692.

The product of its digits is 14336, while the sum is 35.

The square root of 21488147 is about 4635.5309296779. The cubic root of 21488147 is about 278.0137796596.

The spelling of 21488147 in words is "twenty-one million, four hundred eighty-eight thousand, one hundred forty-seven".