21148263 has 8 divisors (see below), whose sum is σ = 31330800. Its totient is φ = 14098824.

The previous prime is 21148249. The next prime is 21148271. The reversal of 21148263 is 36284112.

It is not a de Polignac number, because 21148263 - 2⁶ = 21148199 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 783269 = 21148263 / (2 + 1 + 1 + 4 + 8 + 2 + 6 + 3).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21148213) 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, 391608 + ... + 391661.

It is an arithmetic number, because the mean of its divisors is an integer number (3916350).

Almost surely, 2^21148263 is an apocalyptic number.

21148263 is a deficient number, since it is larger than the sum of its proper divisors (10182537).

21148263 is an equidigital number, since it uses as much as digits as its factorization.

21148263 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 783278 (or 783272 counting only the distinct ones).

The product of its digits is 2304, while the sum is 27.

The square root of 21148263 is about 4598.7240621720. The cubic root of 21148263 is about 276.5401755608.

The spelling of 21148263 in words is "twenty-one million, one hundred forty-eight thousand, two hundred sixty-three".