21448791 has 24 divisors (see below), whose sum is σ = 38132640. Its totient is φ = 11313216.

The previous prime is 21448723. The next prime is 21448793. The reversal of 21448791 is 19784412.

It is not a de Polignac number, because 21448791 - 2¹⁴ = 21432407 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21448793) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 12276 + ... + 13913.

It is an arithmetic number, because the mean of its divisors is an integer number (1588860).

Almost surely, 2^21448791 is an apocalyptic number.

21448791 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21448791 is a deficient number, since it is larger than the sum of its proper divisors (16683849).

21448791 is a wasteful number, since it uses less digits than its factorization.

21448791 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26215 (or 26212 counting only the distinct ones).

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

The square root of 21448791 is about 4631.2839472440. The cubic root of 21448791 is about 277.8439465420.

The spelling of 21448791 in words is "twenty-one million, four hundred forty-eight thousand, seven hundred ninety-one".