21054649 has 16 divisors (see below), whose sum is σ = 26864640. Its totient is φ = 16022160.

The previous prime is 21054643. The next prime is 21054661. The reversal of 21054649 is 94645012.

It is not a de Polignac number, because 21054649 - 2⁵ = 21054617 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21054649.

It is not an unprimeable number, because it can be changed into a prime (21054643) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 132 + ... + 6490.

It is an arithmetic number, because the mean of its divisors is an integer number (1679040).

Almost surely, 2^21054649 is an apocalyptic number.

It is an amenable number.

21054649 is a deficient number, since it is larger than the sum of its proper divisors (5809991).

21054649 is a wasteful number, since it uses less digits than its factorization.

21054649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6420.

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 21054649 is about 4588.5345155071. The cubic root of 21054649 is about 276.1315316847.

The spelling of 21054649 in words is "twenty-one million, fifty-four thousand, six hundred forty-nine".